Cause Of Chronic Fatigue Syndrome
Viruses, Allergens, Faulty Immune System


hay fever causes CFS?
Could hayfever trigger CFS?

Causes Of CFS


What Causes Chronic Fatigue Syndrome?
Faulty Genes
Central Nervous System Disorders
Faulty Immune System
Low Blood Pressure

What Causes Chronic Fatigue Syndrome?

The cause of chronic fatigue syndrome (CFS) is not yet known. At first researchers hoped to find one specific virus that would account for the illness, but they could not find one. Researchers are now investigating various theories. It may turn out that the syndrome is caused by a complex set of events which when they occur in susceptible people, they trigger the condition. In other words, there is no one biological cause that can be tested for.

The Complex Set Of Events

Some experts believe that CFS develops as a result of a convergence of conditions - a number of events that occur together and set off symptoms. These events may include:

• The presense of faulty genes (makes a person susceptible)
• Brain not responding the way it should to hormones
• Over sensitive immune system
• Previous viral infection
• Psychiatric or emotional disorders.

For example, many patients report initially having a viral infection or mental disorder (such as depression) before the onset of their CFS. It may be that these events, alone or working in combination, trigger CFS in people who already have genetic or brain chemical abnormalities.

Faulty Genes

CFS has been linked to faulty genes in the nervous system and hypothalamic-pituitary-adrenal (HPA) axis. Working correctly these genes control response to injury, trauma and other stressful events.

Central Nervous System Disorders

Some patients with CFS have abnormal levels of neurotransmitters (the chemicals that transmit messeges in the brain). Some have abnormally high levels of serotonin (causes chills, headaches and rapid heart rate), or not enough dopamine (causes depression). Or there may be an imbalance between norepinephrine (stress hormone) and dopamine. In most cases routine testing of these hormones is too expensive.

A number of other studies show that CFS patients have lower levels of cortisol, another type of stress hormone. It may be the reason why their body has a weaker response to coping with stress (emotional stress, and stressed caused by infection or physical exercise). However, administering cortisol only improves symptoms in some patients.

Other studies show that CFS is a disorder of the sleep-wake-cycle, our so-called internal clock that tells us when to wake and when to sleep. It may be that a stressful event, mental or physical (such as an infection), disturbs the clock's natural rhythms. An inability to reset the clock causes sleep disturbances and constant exhaustion. Sleeping pills certainly appear very helpful to some patients with CFS.


Nearly 80 percent of CFS cases start with flu-like symptoms. In fact there have been reports of clusters of CFS outbreaks in the same workplaces, community and households. However there is no evidence yet that CFS can spread through casual contact like the common cold or flu virus. Scientists have investigated the possibility of certain viruses triggering CFS in susceptible patients. These viruses include Epstein-Barr, Candida (yeast infection), Lyme disease and measles. The results remain inconclusive.

Faulty Immune System

CFS has sometimes been referred to as chronic fatigue immune dysfunction syndrome. Several studies show that a faulty immune system could be a factor in certain CFS cases. In some, their system is over-reactive, while in others it is under-reactive. Up to 80 percent of people with CFS have allergies (compared to 20 percent of the normal population) to foods, metals (mercury or nickel), pollen (hayfever) or other substances. One theory is that the allergy, like a viral infection, triggers a cascade of responses in the body that leads to CFS.

Low Blood Pressure

Yet more studies reveal that some CFS patients also have a condition called neurally mediated hypotension (NMH). This condition causes a dramatic drop in blood pressure when you stand up, causing you to feel instantly faint and nauseous.

One Condition Or Several?

Scientists have also pondered the question could CFS be more than one condition? Perhaps there are a number of similar chronic fatigue syndromes. These include neurasthenia (severe fatigue and weakness), postviral fatigue syndrome, chronic mononucleosis (also called the Epstein-Barr virus), and myalgic encephalomyelitis (muscle and brain inflammation). Whether or not CFS turns out to be one condition or many, what is known, is that women are twice as likely to be affected, particularly if they already have a disorder of the immune system such as thyroid disease, lupus or multiple sclerosis.

  Related Articles on Chronic Fatigue Syndrome

For more articles, see the following:

Symptoms of chronic fatigue syndrome: Early warning signs.
Diagnosis of chronic fatigue syndrome: Tests and diagnostic criteria.
Treatment for chronic fatigue syndrome: Managing your condition.

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