Chronic fatigue syndrome
What Is Chronic Fatigue Syndrome?
Chronic fatigue syndrome (CFS) is a debilitating disorder characterized by extreme fatigue or
tiredness that doesn’t go away with rest, and can’t be explained by an underlying medical
condition. CFS can also be referred to as myalgic encephalomyelitis (ME) or systemic exertion
intolerance disease (SEID). The causes of CFS aren’t well-understood. Some theories include
viral infection, psychological stress, or a combination of factors. Because no single cause has
been identified, and because many other illnesses produce similar symptoms, CFS can be difficult
to diagnose. There are no tests for CFS, so your doctor will have to rule out other causes for
your fatigue. While CFS has been a controversial diagnosis in the past, it’s now widely accepted
as a real medical condition. CFS can affect anyone, though it’s most common among women in their
40s and 50s. There is no current cure, so treatment for CFS focuses on relieving your symptoms.
What Causes CFS?
The cause of CFS is unknown. Researchers speculate that viruses, hypotension (unusually low
blood pressure), a weakened immune system, and hormonal imbalances could all be contributing
factors. It’s also possible that some people are genetically predisposed to develop CFS. Though
CFS can sometimes develop after a viral infection, no single type of infection has been found to
cause CFS. Some viruses that have been studied in relation to CFS include Epstein-Barr virus
(EBV), human herpesvirus 6, Ross River virus (RRV), rubella, Coxiella burnetti, and mycoplasma.
Researchers have found that a person who has been infected with at least three of the implicated
pathogens has a greater chance of developing CFS. The U.S. Centers for Disease Control and
Prevention (CDC) have suggested that CFS may be the end stage of multiple different conditions,
rather than one unique condition. In fact, 10 to 12 percent of people with Epstein-Barr virus,
Ross River virus, and Coxiella burnetti develop a condition that meets the criteria for a CFS
diagnosis. People with CFS sometimes have weakened immune systems, but doctors don’t know
whether this is enough to cause the disease. Additionally, people with CFS sometimes have
abnormal hormone levels, but doctors haven’t yet concluded whether this is significant.
What Are the Symptoms of CFS?
The symptoms of CFS vary from person to person and based on the severity of the condition. The
most common symptom is fatigue that is severe enough to interfere with your daily activities.
For CFS to be diagnosed, fatigue must last for at least six months and must not be curable with
bed rest, and you must have at least four other symptoms as well.
Other symptoms of CFS may include:
- loss of memory or concentration
- feeling unrefreshed after a night’s sleep
- chronic insomnia (and other sleep disorders)
- muscle pain
- frequent headaches
- multijoint pain without redness or swelling
- frequent sore throat
- tender lymph nodes in your neck and armpits
You may also experience illness or extreme fatigue after physical or mental activities. This can
last for more than 24 hours after the activity. People are sometimes affected by CFS in cycles,
with periods of feeling worse and then better again. Symptoms may sometimes even disappear
completely (remission). However, it’s still possible for them to come back again later
(relapse). The cycle of remission and relapse can make it difficult to manage your symptoms.
How Is CFS Diagnosed?
CFS is a very challenging condition to diagnose. According to the CDC, only 20 percent of the
estimated 1 to 3 million Americans with CFS have been diagnosed. There are no lab tests to
screen for CFS and its symptoms are common to many illnesses. Many people with CFS don’t look
obviously sick, so doctors may not recognize that they are ill. In order to be diagnosed with
CFS, you must have at least four of the above symptoms listed. You also must have severe,
unexplained fatigue that cannot be cured with bed rest. The fatigue and other symptoms must last
for six months or longer.
Ruling out other potential causes of your
fatigue is a key part of the diagnosis process. Some conditions whose symptoms resemble those of
CFS include:
- mononucleosis
- Lyme disease
- multiple sclerosis
- lupus (SLE)
- hypothyroidism
- fibromyalgia
- major depressive disorder
You may also experience symptoms of CFS if you are severely obese or have depressive disorders or
sleep disorders. The side effects of certain drugs, such as antihistamines and alcohol, can
mimic CFS as well. Because the symptoms of CFS resemble those of other conditions, it’s
important not to self-diagnose and to talk to your doctor.