Researchers have been discovering more and more about CFS - what possibly causes it, why certain people and not others get it, and how it takes root - but they don’t have any definitive answers. Basically, a variety of causes are being investigated, any one of which may someday be shown to be the illness’s raison d’être. These possible causes of CFS include the following:
Your family history: If another family member had CFS (or some of the symptoms of CFS), you may be more vulnerable to getting it; however, the jury’s still out as to whether there’s a genetic link. Some people with CFS in their family history live their whole lives without getting CFS.
Stress, stress, and more stress: This possible cause can mean day-to-day mental or emotional stress or stressors such as illness or injury. You may have a genetic connection between your symptoms and the way your hormones react to stress. Basically, this hormonal reaction comes down to allostatic load (or AL for those in the know). AL measures the wear and tear your body goes through when stress rears its anxious head. Some early studies have reported that people with CFS may have a problem with the physical mechanism that generates a proper stress response, rendering them unable to react effectively to stressors (mental or physical).
Body chemistry: Humans have an amazing messenger system — one that beats FedEx hands down. Your body produces chemicals in response to messages sent to and from the brain — chemicals that don’t miss a beat when it comes to getting a good night’s sleep or hailing a cab or deciding whether to get that dress in the store window. But as good as your chemical messenger service is, it can get out of whack — whether stress, illness, or emotion is the cause. Think of this chemical imbalance as a blizzard that stops the mail from coming in, one that may or may not bring CFS with it.
Viral infections: You have a powerful immune system in your body, with antibodies and natural killer (NK) cells just salivating for some foreign virus to dare enter your cells. But unfortunately, your immune system isn’t always perfect. It can fail to attack with the full force of its fury, not recognize the virus as an enemy, or may even overreact. This whacked-out immune system has also been linked to CFS.
Sleep problems: Yes, it’s true: Whether your sleep issues are due to stress, an overtaxed and overworked immune system with no downtime to rest, or just the lack of quality sleep in general, problems with sleep have been linked to CFS.
The HPA axis: Doctors call the hypothalamus in your brain, along with your pituitary and adrenal glands, the hypothalamus-pituitary-adrenal (HPA) axis. The hypothalamus sends messages to the pituitary gland via hormonal (chemical) messengers. The pituitary gland, in turn, triggers the production of hormones in your ovaries or testes, adrenals, and thyroid glands. Some people with CFS appear to have abnormally low levels of the hormone cortisol in the blood, which means that a malfunction in the HPA axis may be a possible cause.
Inflammation: Think of an inflammation as the way your body fends off viruses and bacteria — the first line of defense in the immune system. However, chronic inflammation can break down the immune system, which may result in CFS.
Autonomic nervous system dysregulation: Your autonomic nervous system is responsible for all your critical body functions, from breathing and regulating your heartbeat to keeping your temperature on an even keel. Some people who develop CFS have an autonomic nervous system problem called orthostatic instability (OI), which means that staying in an upright position for more than a few minutes results in a feeling of dizziness; this feeling can occur when sitting or standing up. Because OI can be caused by dysfunction in the autonomic nervous system, your autonomic nervous system could somehow be involved in your CFS. However, some physicians believe that OI stands alone, a condition in and of itself; still others consider OI a symptom of CFS, not a cause.
Physical trauma: Ouch! The aches and pains of a fall or an accident can hurt your bones, muscles, and even your brain. Not only can physical pain lead to all sorts of not-so-fun things — such as insomnia, depression, brain dysfunction, or even changes on a very basic cellular level in your body — but it has also been explored as a cause, trigger, or perpetuating factor in some cases of CFS.
Ongoing infection: Sometimes the flu you caught at the office doesn’t go away in the requisite two weeks. Sometimes the infection lingers...and lingers. And instead of feeling better, you feel steadily worse. Infection has long been suspected as a cause or trigger of CFS, but researchers haven’t identified a specific virus or bacteria as of yet. It could be that by the time a person goes to the doctor after many weeks or months of symptoms, the bug is gone, leaving various forms of damage in its wake.
Environmental toxins and allergies: Pollen, dander, mercury, and lead — these damaging substances may be involved in the onset of CFS in the same way infections are.