Stress

Stress Symptoms, Signs, and Causes

Understanding Stress, its Harmful Effects, and the Best Ways to Cope

Modern life is full of frustrations, deadlines, and demands. For many people, stress is so commonplace that it has become a way of life. Stress isn’t always bad, though. Stress within your comfort zone can help you perform under pressure, motivate you to do your best, even keep you safe when danger looms. But when stress becomes overwhelming, it can damage your health, mood, relationships, and quality of life.
You can protect yourself by understanding how the body’s stress response works, recognizing the signs and symptoms of stress overload, and taking steps to reduce its harmful effects.

What is stress?

Stress is your body’s way of responding to any kind of demand or threat. When you feel threatened, your nervous system responds by releasing a flood of stress hormones, including adrenaline and cortisol, which rouse the body for emergency action. Your heart pounds faster, muscles tighten, blood pressure rises, breath quickens, and your senses become sharper. These physical changes increase your strength and stamina, speed your reaction time, and enhance your focus.
This is known as the “fight or flight” stress response and is your body’s way of protecting you. When working properly, stress helps you stay focused, energetic, and alert. In emergency situations, stress can save your life—giving you extra strength to defend yourself, for example, or spurring you to slam on the brakes to avoid an accident.
Stress can also help you rise to meet challenges. Stress is what keeps you on your toes during a presentation at work, sharpens your concentration when you’re attempting the game-winning free throw, or drives you to study for an exam when you'd rather be watching TV.
But beyond your comfort zone, stress stops being helpful and can start causing major damage to your mind and body.

How do you respond to stress?

The latest research into the brain shows that we, as mammals, have three ways of regulating our nervous systems and responding to stress:

• Social engagement is our most evolved strategy for keeping ourselves feeling calm and safe. Since the vagus nerve connects the brain to sensory receptors in the ear, eye, face and heart, socially interacting with another person—making eye contact, listening in an attentive way, feeling understood—can calm you down and put the brakes on defensive responses like “fight-or-flight.” When using social engagement, you can think and feel clearly, and body functions such as blood pressure, heartbeat, digestion, and the immune system continue to work uninterrupted.
• Mobilization, otherwise known as the fight-or-flight response. When social engagement isn’t an appropriate response and we need (or think we need) to either defend ourselves or run away from danger, the body prepares for mobilization. It releases chemicals to provide the energy you need to protect yourself. At the same time, body functions not needed for fight or flight—such as the digestive and immune systems—stop working. Once the danger has passed, your nervous system calms the body, slowing heart rate, lowering blood pressure, and winding back down to its normal balance.
• Immobilization. This is the least evolved response to stress and used by the body only when social engagement and mobilization have failed. You may find yourself traumatized or “stuck” in an angry, panic-stricken or otherwise dysfunctional state, unable to move on. In extreme, life-threatening situations, you may even lose consciousness, enabling you to survive high levels of physical pain. However, until you’re able to arouse your body to a mobilization response, your nervous system may be unable to return to its pre-stress state of balance.

While it’s not always possible to respond to stress using social engagement, many of us have become conditioned to responding to every minor stressor by immediately resorting to fight or flight. Since this response interrupts other body functions and clouds judgment and feeling, over time it can cause stress overload and have a detrimental effect on both your physical and mental health.

Effects of stress overload

The body’s autonomic nervous system often does a poor job of distinguishing between daily stressors and life-threatening events. If you’re stressed over an argument with a friend, a traffic jam on your commute to work, or a mountain of bills, for example, your body can still react as if you’re facing a life-or-death situation.
When you repeatedly experience the fight or flight stress response in your daily life, it can raise blood pressure, suppress the immune system, increase the risk of heart attack and stroke, speed up the aging process and leave you vulnerable to a host of mental and emotional problems.

Many health problems are caused or exacerbated by stress, including:

Pain of any kind Heart disease Digestive problems Sleep problems

Depression Weight problems Auto immune diseases Skin conditions, such as eczema

Signs and symptoms of stress overload

The following table lists some of the common warning signs and symptoms of chronic stress. The more signs and symptoms you notice in yourself, the closer you may be to stress overload.

Cognitive Symptoms

Memory problems Inability to concentrate Poor judgment Seeing only the negative Anxious or racing thoughts Constant worrying

Emotional Symptoms

Moodiness Irritability or short temper Agitation, inability to relax Feeling overwhelmed Sense of loneliness and isolation Depression or general unhappiness

Physical Symptoms

Aches and pains Diarrhea or constipation Nausea, dizziness Chest pain, rapid heartbeat Loss of sex drive Frequent colds

Behavioral Symptoms

Eating more or less Sleeping too much or too little Isolating yourself from others Procrastinating or neglecting responsibilities Using alcohol, cigarettes, or drugs to relax Nervous habits (e.g. nail biting, pacing)

Keep in mind that the signs and symptoms of stress overload can also be caused by other psychological or medical problems. If you’re experiencing any of the warning signs of stress, it’s important to see a doctor to help determine if your symptoms are stress-related.

The causes of stress

Isolation and stress

Since social engagement appears to be our best defense against stress, isolation or a lack of positive, consistent human interaction can be both a stressor in itself and exacerbate other causes of stress.

The situations and pressures that cause stress are known as stressors. We usually think of stressors as being negative, such as an exhausting work schedule or a rocky relationship. However, anything that puts high demands on you or forces you to adjust can be stressful. This includes positive events such as getting married, buying a house, going to college, or receiving a promotion.
Of course, not all stress is caused by external factors. Stress can also be self-generated, for example, when you worry excessively about something that may or may not happen, or have irrational, pessimistic thoughts about life.

Common external causes of stress

Major life changes Work or school Relationship difficulties Financial problems Being too busy Children and family

Common internal causes of stress

Chronic worry Pessimism Negative self-talk Unrealistic expectations/Perfectionism Rigid thinking, lack of flexibility All-or-nothing attitude

What causes excessive stress depends, at least in part, on your perception of it. Something that's stressful to you may not faze someone else; they may even enjoy it. For example, your morning commute may make you anxious and tense because you worry that traffic will make you late. Others, however, may find the trip relaxing because they allow more than enough time and enjoy listening to music while they drive.

Everyone experiences stress differently
Karen is terrified of getting up in front of people to perform or speak, while her best friend, Nin, lives for the spotlight.
Phil thrives under pressure and performs best when he has a tight deadline, while his co-worker,Matt, shuts down when work demands escalate.
Anita enjoys helping her elderly parents. Her sister, Constance, helps out as well but finds the demands of caretaking very stressful.
Richard doesn’t hesitate to send food back or complain about bad service when eating out, while his wife, Miranda, finds it much too stressful to complain.

What determines your ability to manage stress?

We're all different. Some people seem to be able to roll with life’s punches, while others tend to crumble in the face of far smaller obstacles or frustrations. Some people even seem to thrive on the excitement and challenge of a high-stress lifestyle.
Your ability to tolerate stress depends on many factors, including the quality of your relationships and support network, your life experiences, your emotional intelligence, and genetics.

Factors that influence your stress tolerance

• Your support network – Social engagement is the body’s most evolved strategy for responding to stress so it’s no surprise that people with a strong network of supportive friends and family members are better able to cope with life’s stressors. On the flip side, the more lonely and isolated you are, the less opportunity you have to utilize social engagement and the greater your vulnerability to stress.
• Your exercise levels. Your physical and mental health are intrinsically linked, so the better you take care of your body, the greater resilience you’ll have against the symptoms of stress. Exercising regularly (for 30 minutes or more on most days) can lift your mood and help relieve stress, anxiety, anger, and frustration. It can also serve as a distraction to your worries, allowing you to find some quiet time and break out of the cycle of negative thoughts that feed stress and anxiety.
• Your diet. The food you eat can also have a profound effect on your mood and how well you cope with life’s stressors. Eating a diet full of processed and convenience food, refined carbohydrates, and sugary snacks can worsen symptoms of stress while eating a diet rich in fresh fruit and vegetables, high-quality protein, and healthy fats, especially omega-3 fatty acids, can help you better cope with life’s ups and downs.
• Your sense of control – It may be easier to take stress in your stride if you have confidence in yourself and your ability to influence events and persevere through challenges. If you feel like things are out of your control, you’re likely to have less tolerance for stress.
• Your attitude and outlook – Optimistic people are often more stress-hardy. They tend to embrace challenges, have a strong sense of humor, and accept that change is a part of life.
• Your ability to deal with your emotions – You’re extremely vulnerable to stress if you don’t know how to calm and soothe yourself when you’re feeling sad, angry, or overwhelmed by a situation. The ability to bring your emotions into balance helps you bounce back from adversity and is a skill that can be learned at any age.
• Your knowledge and preparation – The more you know about a stressful situation, including how long it will last and what to expect, the easier it is to cope. For example, if you go into surgery with a realistic picture of what to expect post-op, a painful recovery will be less traumatic than if you were expecting to bounce back immediately.

How well do you handle stress in your life?

1. I have people I confide in when I’m feeling under pressure who make me feel better.
2. I feel comfortable expressing how I feel when something is bothering me.
3. In general, I feel in control of my life and confident in my ability to handle what comes my way.
4. I find reasons to laugh and feel grateful, even when going through difficulties.
5. No matter how busy I am, I make it a priority to sleep, exercise, and eat right.
6. I’m able to calm myself down when I start to feel overwhelmed.

Each “yes” answer represents an important stress coping skill. Each “no” represents an area to work on to become more resilient.

Dealing with stress and its symptoms

While unchecked stress is undeniably damaging, you have more control than you might think. Unfortunately, many people cope with stress in ways that only compound the problem. They drink too much to unwind at the end of a stressful day, fill up on comfort food, zone out in front of the TV or computer for hours, use pills to relax, or lash out at other people. However, there are many healthier ways to cope with stress and its symptoms.

Learn how to manage stress

You may feel like the stress in your life is out of your control, but you can always control the way you respond. Stress management can teach you healthier ways to cope with stress, help you reduce its harmful effects, and prevent stress from spiraling out of control again in the future.

• Engage socially. The simple act of talking face to face with another human being can release hormones that reduce stress even if you’re still unable to alter the stressful situation. Opening up to someone is not a sign of weakness and it won’t make you a burden to others. In fact, most friends will be flattered that you trust them enough to confide in them, and it will only strengthen your bond.
• Get moving. Physical activity plays a key role in managing stress. Activities that require moving both your arms and your legs are particularly effective. Walking, running, swimming, dancing, and aerobic classes are good choices, especially if you exercise mindfully (focusing your attention on the physical sensations you experience as you move). Focused movement helps to get your nervous system back into balance. If you’ve been traumatized or experienced the immobilization stress response, getting active can help you to become "unstuck."

Lifestyle changes to deal with the symptoms of stress

You can also better cope with the symptoms of stress by strengthening your physical health.

• Set aside relaxation time. Relaxation techniques such as yoga, meditation, and deep breathing activate the body’s relaxation response, a state of restfulness that is the opposite of the fight or flight stress response.
• Eat a healthy diet. Well-nourished bodies are better prepared to cope with stress. Start your day with a healthy breakfast, reduce your caffeine and sugar intake, add plenty of fresh fruit and vegetables, and cut back on alcohol and nicotine.
• Get plenty of sleep. Feeling tired can increase stress by causing you to think irrationally. Keep your cool in stressful situations by getting a good night’s sleep.

ISCHEMIC HEART DISEASE

Coronary Artery Disease

Cardiac ischemia occurs when plaque and fatty matter narrow the inside of an artery to a point where it cannot supply enough oxygen-rich blood to meet your heart's needs. Heart attacks can occur - with or without chest pain and other symptoms.What Is Ischemia?

Ischemia is most commonly experienced during:

• Exercise or exertion
• Eating
• Excitement or stress
• Exposure to cold

Coronary artery disease can progress to a point where ischemia occurs even at rest. And ischemia can occur without any warning signs in anyone with heart disease, although it is more common in people with diabetes.

What Are the Symptoms of Coronary Artery Disease?

The most common symptom of coronary artery disease is angina, or chest pain. Angina can be described as a heaviness, pressure, aching, burning, numbness, fullness, squeezing or painful feeling. It can be mistaken for indigestion or heartburn. Angina is usually felt in the chest, but may also be felt in the left shoulder, arms, neck, back, or jaw.

Other symptoms that can occur with coronary artery disease include:

• Shortness of breath
• Palpitations (irregular heart beats, skipped beats, or a "flip-flop" feeling in your chest)
• A faster heartbeat
• Weakness or dizziness
• Nausea
• Sweating

How Is Coronary Artery Disease Diagnosed?

Your doctor can tell if you have coronary artery disease by:

• Talking to you about your symptoms, medical history, and risk factors.
• Performing a physical exam.
• Performing diagnostic tests, including an electrocardiogram (ECG or EKG), exercisestress tests, electron beam (ultrafast) CT scans,cardiac catheterization, and others. These tests help your doctor evaluate the extent of your coronary heart disease, its effect on the function of your heart and the best form of treatment for you.

How Is Coronary Artery Disease Treated?

Treatment for coronary artery disease involves making lifestyle changes, taking medications, possibly undergoing invasive and/or surgical procedures, and seeing your cardiologist for regular checkups.

• Reduce your risk factors. If you smoke, quit. Avoid processed foods and adopt a low-trans-fat, low-salt, and low-sugar diet. Keep yourblood sugar in control if you have diabetes. Exercise regularly (but talk to your doctor before you starting an exercise program).
• Medications. If making lifestyle changes isn't enough to manage your heart disease, medications may be needed to help your heart work more efficiently and receive more oxygen-rich blood. The drugs you are on depend on you and your specific heart problem.
• Surgery and other procedures. Common procedures to treat coronary artery disease include balloon angioplasty (PTCA), stentplacement, and coronary artery bypass surgery. All of these procedures increase blood supply to your heart, but they do not cure coronary heart disease. You will still need to decrease your risk factors to prevent future disease.

Doctors are also studying several innovative ways to treat heart disease. Here are a couple of the more promising ones:

• Angiogenesis. This involves giving substances, such as stem cells and other genetic material, through the vein or directly into damaged heart tissue to trigger the growth of new blood vessels to bypass the clogged ones.
• EECP (Enhanced External Counterpulsation). Patients who have chronic angina but are not helped by nitrate medications or who do not qualify for various surgeries and procedures may find relief with EECP. The outpatient procedure involves using treatment cuffs placed on the legs that inflate and deflate, increasing the blood supply that feeds coronary arteries.

Zika Virus

Zika virus

Zika virus is a flavivirus, closely related to dengue. Cases of Zika virus have previously been reported in Africa, southern Asia and the Pacific Islands. Beginning in 2014, Zika virus outbreaks have occurred throughout the tropical and sub-tropical areas of the western hemisphere, as far north as Mexico and Puerto Rico.

Because Zika, dengue and chikungunya viruses are transmitted by mosquitoes mostly active during daytime, it's important that all travelers visiting affected areas continue to take protective measures to prevent mosquito bites throughout the day.  

Zika virus infection is symptomatic in only about 1 out of every 5 cases. When symptomatic, Zika infection usually presents as an influenza-like syndrome, often mistaken for other arboviral infections like dengue or chikungunya.

New Zealand currently has 15 mosquito species. The mosquito species (Aedes sp.) that are able to spread Zika virus are not normally found in New Zealand however they are found in many other countries around the world.

A national mosquito surveillance programme has been operating for some years at New Zealand's international points of entry (ports and airports). The ports and airports are monitored regularly throughout the year to ensure the early detection of any exotic mosquitoes.

On 1 February 2016 the World Health Organization (WHO) declared a Public Health Emergency of International Concern (PHEIC) regarding a recent cluster of microcephaly cases and other neurological disorders and the possible association of these illnesses with Zika virus infections. The WHO recommended efforts towards improved surveillance of and education regarding Zika virus as well as promotion of mosquito control. The WHO recommended no restrictions on travel or trade.

---

Zika virus and pregnancy

• Related to Pregnancy

There are concerns that pregnant women who become infected with Zika virus can transmit the disease to their unborn babies, with potentially serious consequences. Reports from several countries, most notably Brazil, demonstrate an increase in severe fetal birth defects and poor pregnancy outcomes in babies whose mothers were infected with Zika virus while pregnant.

Additional international research is necessary and ongoing to determine the link between Zika virus and fetal damage.

Until more is known, the Ministry of Health recommends that women who are pregnant or plan to become pregnant in the near term consider delaying travel to areas with Zika virus present. If travel is essential, consider delaying pregnancy if travelling to these areas.

If travelling in Zika infected areas, women who are pregnant or plan to become pregnant should consult with their healthcare provider. All travelers should take all precautions to avoid mosquito bites, including:

• Wear long-sleeved shirts and long pants.
• Use insect repellents containing DEET, picaridin, oil of lemon eucalyptus (OLE), or IR3535. Always use as directed.
• Insect repellents containing DEET, picaridin, and IR3535 are safe for pregnant and breastfeeding women and children older than 2 months when used according to the product label. Oil of lemon eucalyptus products should not be used on children under 3 years of age.
• If you use both sunscreen and insect repellent, apply the sunscreen first and then the repellent.
• Use permethrin-treated clothing and gear (such as boots, pants, socks, and tents).
• Use bed nets as necessary.
• Stay and sleep in screened-in or air-conditioned rooms.
• Be particularly vigilant for the 2 hours after sunrise and the 2 hours before sunset.

We also advise that women who have travelled to an affected country without their partner use appropriate contraception for four weeks to avoid pregnancy. However, if the partner has also travelled to an affected country then see advice on sexual transmission of Zika virus.

If you are pregnant and develop a rash, red eyes, fever, or joint pain within 14 days of travel to a Zika virus infected country, please consult your health care provider and let them know your travel history.

This information will be updated as more research becomes available.

Sexual transmission of Zika virus

There is only limited information available about the risk of sexual transmission of Zika virus, but the risk is considered to be low when compared to the risk of transmission from infected mosquitoes.

Due to the potentially serious implications of transmitting Zika to a pregnant woman, we advise that:

• All men who have travelled to a Zika-affected area and have a pregnant partner should abstain from sexual activity (oral, vaginal, and anal) or use condoms for the duration of the pregnancy, whether they have symptoms or not.
• All men who have travelled to a Zika-affected area and have a partner who is at risk of becoming pregnant should abstain from sexual activity (oral, vaginal, and anal) or use condoms, whether they have symptoms or not. International advice about how long to abstain varies:
  • at least four weeks (WHO)
  • 3 months (Australian Department of Health)
  • 6 months (ECDC and Public Health England)
  • no specific duration mentioned (CDC).

We will continue to review New Zealand guidance as further information becomes available.

---

Symptoms of Zika virus infection

• low-grade fever
• arthralgia, notably of small joints of hands and feet, with possible swollen joints
• myalgia
• headache, retro-ocular headaches
• conjunctivitis
• cutaneous maculopapular rash

Zika virus infection usually causes a mild disease (with the possible exception in pregnant women, as discussed below). However, as Zika infection may cause a rash that could be confused with diseases such as measles or dengue, these serious diseases do need to be ruled out. Diagnosis of Zika will first and foremost be based on symptoms, travel history and exclusion of other diseases including measles, rubella and dengue.

The incubation period is typically 3–12 days. There is no specific therapy for Zika virus infection and acute symptoms typically resolve within 4–7 days. Use paracetamol for pain and fever if needed. Until dengue can be ruled out do not take aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, given the risk of bleeding.

---

Laboratory testing

What types of testing for Zika virus are available to test pregnant women?

Reverse-transcriptase PCR (RT-PCR) can be used to detect the Zika virus during the first 1 week (in blood) to 4 weeks (in urine) of the illness. This RT-PCR test is currently performed in Wellington at ESR, Auckland at Labplus, and Christchurch at Canterbury Health Laboratories, with an expected turnaround time of 2 working days.

Serology is less reliable due to potential cross reaction with antibodies against other similar viruses (including dengue). This makes it difficult to differentiate Zika virus infection using antibody testing alone. For this reason, Zika virus serology is not recommended at this time as part of the algorithm for assessing pregnant women with a history of travel to areas with active Zika virus transmission. If Zika serology is being requested a discussion with a microbiologist needs to occur prior to testing.

Zika virus RT-PCR can also be performed on amniotic fluid although it is not currently known how sensitive or specific this test is for congenital infection. The likelihood of an infected fetus developing a fetal abnormality is not known at this time

Guillain–Barre syndrome (GBS)

Guillain–Barre syndrome (GBS) is a rapid-onset muscle weakness caused by the immune system damaging the peripheral nervous system. Many experience changes in sensation or develop pain, followed by muscle weakness beginning in the feet and hands. The symptoms develop over half a day to two weeks. During the acute phase, the disorder can be life-threatening with about a quarter developing weakness of the breathing muscles and requiring mechanical ventilation. Some are affected bychanges in the function of the autonomic nervous system, which can lead to dangerous abnormalities in heart rate and blood pressure.

This autoimmune disease is caused by the body's immune system mistakenly attacking the peripheral nerves and damaging theirmyelin insulation. Sometimes this immune dysfunction is triggered by an infection. The diagnosis is usually made based on the signs and symptoms, through the exclusion of alternative causes, and supported by tests such as nerve conduction studies and examination of the cerebrospinal fluid. Various classifications exist, depending on the areas of weakness, results of nerve conduction studies, and the presence of antiganglioside antibodies. It is classified as an acute polyneuropathy.

In those with severe weakness, prompt treatment with intravenous immunoglobulins or plasmapheresis, together with supportive care, will lead to good recovery in the majority. Some may experience ongoing difficulty with walking, painful symptoms, and some require long-term breathing support.

Signs and symptoms

The first symptoms of Guillain–Barré syndrome are numbness, tingling, and pain, alone or in combination. This is followed by weakness of the legs and arms that affects both sides equally and worsens over time. The weakness can take half a day to over two weeks to reach maximum severity, and then becomes steady.In one in five people, the weakness continues to progress for as long as four weeks.The muscles of the neck may also be affected, and about half experience involvement of the cranial nerves which supply the head and face; this may lead to weakness of the muscles of the face, swallowing difficulties and sometimes weakness of the eye muscles.In 8%, the weaknessaffects only the legs (paraplegia or paraparesis). Involvement of the muscles that control the bladder and anus is unusual. In total, about a third of people with Guillain–Barré syndrome continue to be able to walk. Once the weakness has stopped progressing, it persists at a stable level ("plateau phase") before improvement occurs. The plateau phase can take between two days and six months, but the most common duration is a week. Pain-related symptoms affect more than half, and include back pain, painful tingling, muscle pain and pain in the head and neck relating to irritation of the lining of the brain.

Many people with Guillain–Barré syndrome have experienced the signs and symptoms of an infection in the 3–6 weeks prior to the onset of the neurological symptoms. This may consist of upper respiratory tract infection (rhinitis, sore throat) or diarrhea.

In children, particularly those younger than six years old, the diagnosis can be difficult and the condition is often initially mistaken (sometimes for up to two weeks) for other causes of pains and difficulty walking, such as viral infections, or bone and joint problems.

On neurological examination, characteristic features are the reduced power and reduced or absent tendon reflexes (hypo- or areflexia, respectively). However, a small proportion has normal reflexes in affected limbs before developing areflexia, and some may have exaggerated reflexes.In the "Miller Fisher variant" subtype of Guillain–Barré syndrome (see below), weakness of the eye muscles (ophthalmoplegia) is more pronounced and may occur together with abnormalities in coordination (ataxia). The level of consciousness is normally unaffected in Guillain–Barré syndrome, but the Bickerstaff brainstem encephalitis subtype may feature drowsiness, sleepiness, or coma.

Respiratory failure

A quarter of all people with Guillain–Barré syndrome develop weakness of the breathing muscles leading to respiratory failure, the inability to breathe adequately to maintain healthy levels of oxygen and/or carbon dioxide in the blood.^[1][2][6] This life-threatening scenario is complicated by other medical problems such as pneumonia, severe infections,blood clots in the lungs and bleeding in the digestive tract in 60% of those who require artificial ventilation.

Autonomic dysfunction

The autonomic or involuntary nervous system, which is involved in the control of body functions such as heart rate and blood pressure, is affected in two thirds of people with Guillain–Barré syndrome, but the impact is variable. Twenty percent may experience severe blood-pressure fluctuations and irregularities in the heart beat, sometimes to the point that the heart beat stops and requiring pacemaker-based treatment. Other associated problems are abnormalities in perspiration and changes in the reactivity of the pupils. Autonomic nervous system involvement can affect even those who do not have severe muscle weaknes

Causes

A scanning electron microscope-derived image of Campylobacter jejuni, which triggers about 30% of cases of Guillain–Barré syndrome

Two thirds of people with Guillain–Barré syndrome have experienced an infection before the onset of the condition. Most commonly these are episodes of gastroenteritis or a respiratory tract infection. In many cases, the exact nature of the infection can be confirmed.^[2]Approximately 30% of cases are provoked by Campylobacter jejuni bacteria, which cause diarrhea. A further 10% are attributable tocytomegalovirus (CMV, HHV-5). Despite this, only very few people with Campylobacter or CMV infections develop Guillain–Barré syndrome (0.25–0.65 per 1000 and 0.6–2.2 per 1000 episodes, respectively). The strain of Campylobacter involved may determine the risk of GBS; different forms of the bacteria have different lipopolysaccharides on their surface, and some may induce illness while others will not.

Links between other infections and GBS are less certain. Two other herpesviruses (Epstein–Barr virus/HHV-4 and varicella zoster virus/HHV-3) and the bacterium Mycoplasma pneumoniae have been associated with GBS.The tropical viral infection dengue fever has been associated with episodes of GBS. Previous hepatitis E virus infection has been found to be more common in people with Guillain–Barré syndrome.Zika virus has been linked to Guillain–Barré syndrome.

Some cases may be triggered by the influenza virus and potentially influenza vaccine. An increased incidence of Guillain–Barré syndrome followed influenza immunization that followed the 1976 swine flu outbreak (H1N1 A/NJ/76); 8.8 cases per million recipients developed the complication. Since then, close monitoring of cases attributable to vaccination has demonstrated that influenza itself can induce GBS. Small increases in incidence have been observed in subsequent vaccination campaigns, but not to the same extent. The 2009 flu pandemic vaccine (against pandemic swine flu virus H1N1/PDM09) did not cause a significant increase in cases. It is considered that the benefits of vaccination in preventing influenza outweigh the small risks of GBS after vaccination. Even those who have previously experienced Guillain–Barré syndrome are considered safe to receive the vaccine in the future.Other vaccines, such as those againstpoliomyelitis, tetanus or measles, have not been associated with a risk of GBS

Diagnosis

The diagnosis of Guillain–Barré syndrome depends on findings such as rapid development of muscle paralysis, absent reflexes, absence of fever, and a likely cause. Cerebrospinal fluid analysis (through a lumbar spinal puncture) and nerve conduction studies are supportive investigations commonly performed in the diagnosis of GBS.Testing for antiganglioside antibodies is often performed, but their contribution to diagnosis is usually limited. Blood tests are generally performed to exclude the possibility of another cause for weakness, such as a low level of potassium in the blood. An abnormally low level of sodium in the blood is often encountered in Guillain–Barré syndrome. This has been attributed to the inappropriate secretion of antidiuretic hormone, leading to relative retention of water.

In many cases, magnetic resonance imaging of the spinal cord is performed to distinguish between Guillain–Barré syndrome and other conditions causing limb weakness, such as spinal cord compression. If an MRI scan shows enhancement of the nerve roots, this may be indicative of GBS.In children, this feature is present in 95% of scans, but it is not specific to Guillain–Barré syndrome, so other confirmation is also needed

Treatment

Immunotherapy

Plasmapheresis and intravenous immunoglobulins (IVIg) are the two main immunotherapy treatments for GBS. Plasmapheresis attempts to reduce the body's attack on the nervous system by filtering antibodies out of the bloodstream. Similarly, administration of IVIg neutralizes harmful antibodies and inflammation. These two treatments are equally effective and a combination of the two is not significantly better than either alone. Plasmapheresis speeds recovery when used within four weeks of the onset of symptoms.IVIg works as well as plasmapheresis when started within two weeks of the onset of symptoms, and has fewer complications. IVIg is usually used first because of its ease of administration and safety. Its use is not without risk; occasionally it causes liver inflammation, or in rare cases, kidney failure. Glucocorticoids alone have not been found to be effective in speeding recovery and could potentially delay recovery.

Respiratory failure

Respiratory failure may require intubation of the windpipe and breathing support through mechanical ventilation, generally on an intensive care unit. The need for ventilatory support can be anticipated by measurement of two spirometry-based breathing tests: the forced vital capacity (FVC) and the negative inspiratory force (NIF). An FVC of less than 15 ml per kilogram body weight or an NIF of less than 60 cmH₂O are considered markers of severe respiratory failure.

Pain

While pain is common in people with Guillain–Barré syndrome, studies comparing different types of pain medication are insufficient to make a recommendation as to which should be used.

Rehabilitation

Following the acute phase, around 40% of people require intensive rehabilitation with the help of a multidisciplinary team to focus on improving activities of daily living (ADLs).Studies into the subject have been limited, but it is likely that intensive rehabilitation improves long-term symptoms. Teams may include physical therapists, occupational therapists, social workers, psychologists, other allied health professionals and nurses. The team usually works under the supervision of a neurologist or rehabilitation physiciandirecting treatment goals

Physiotherapy interventions include strength, endurance and gait training with graduated increases in mobility, maintenance of posture and alignment as well as joint function. Occupational therapy aims to improve everyday function with domestic and community tasks as well as driving and work. Psychologists may provide counseling and support. Home modifications, gait aids, orthotics and splints may be provided. Speech-language pathology input may be required in those with speech and swallowing problems, as well as to support communication in those who require ongoing breathing support (often through a tracheostomy). Nutritional support may be provided by the team and by dietitians. Psychological interventions may be required for anxiety, fear and depression.

Prognosis

Guillain–Barré syndrome can lead to death as a result of a number of complications: severe infections, blood clots, and cardiac arrest likely due to autonomic neuropathy. Despite optimum care this occurs in about 5% of cases.

There is a variation in the rate and extent of recovery.The prognosis of Guillain–Barré syndrome is determined mainly by age (those over 40 may have a poorer outcome), and by the severity of symptoms after two weeks. Furthermore, those who experienced diarrhea before the onset of disease have a worse prognosis. On the nerve conduction study, the presence of conduction block predicts poorer outcome at 6 months. In those who have received intravenous immunoglobulins, a smaller increase in IgG in the blood two weeks after administration is associated with poorer mobility outcomes at six months than those whose IgG level increased substantially. If the disease continues to progress beyond four weeks, or there are multiple fluctuations in the severity (more than two in eight weeks), the diagnosis may be chronic inflammatory demyelinating polyneuropathy which is treated differently.

In research studies, the outcome from an episode of Guillain–Barré syndrome is recorded on a scale from 0–6, where 0 denotes completely healthy, 1 very minor symptoms but able to run, 2 able to walk but not to run, 3 requiring a stick or other support, 4 confined to bed or chair, 5 requiring long-term respiratory support, 6 death.

The health-related quality of life (HRQL) after an attack of Guillain–Barré syndrome can be significantly impaired. About a fifth are unable to walk unaided after six months, and many experience chronic pain, fatigue and difficulty with work, education, hobbies and social activities. HRQL improves significantly in the first year,