Chronic fatigue syndrome is a medical condition wherein the patient feels persistent fatigue that cannot be relieved with rest, for already about six months. Other symptoms include sleep difficulties, cognitive impairment, impaired concentration, sore throat, tender glands, stiff muscles, multijoint pain, and headaches. A person with this condition always feels tired and therefore cannot function properly in his/her daily life.

Studies have show that chronic fatigue syndrome is a relatively rare condition. It is estimated that there are half a million people in the US have chronic fatigue syndrome while only a quarter in UK. The prevalence rate of the condition is approximately 1 in 544 or 0.18% of the population in the USA.

Most of those who have this condition are adults as it usually develops in the early 20s to mid 40s. However, children and adolescents can also be affected by this condition, although at a lower rate. Statistics also show that women are more prone to chronic fatigue syndrome as they are four times more likely to have the condition.

Social class can also factor in the prevalence of chronic fatigue syndrome. It is found out that people from the lower socioeconomic classes are more likely to be fatigued. This may be due to the fact that they are prone to social adversity, a known predictor of fatigue. Community surveys have also shown that Caucasians have lower risk of having the condition compared with Latinos, African Americans, and Native Americans.

It is also observed that there are family members who have developed chronic fatigue syndrome, suggesting that the condition is a genetic predisposition. However, there is not enough evidence to support this claim.

Other people that are known to be susceptible to this condition are those who were infected with virus, Gulf War veterans, and high-risk occupational groups such as health workers, airline pilots, and shift workers.
The future of those who have chronic fatigue syndrome is also grim as only 5-10% of the cases fully recovers from the condition. However, through the right combination of treatments, the symptoms of the condition can still be managed, allowing the patient to function again in his/her daily life.