What Are the Symptoms of Chronic Fatigue Syndrome
CFS symptoms extend well beyond everyday tiredness. Most patients experience a cluster of symptoms that can last for years and significantly limit daily functioning, even though they may not “look sick” to others.
Important: CFS symptoms can persist for years and result in serious disability. If your fatigue has lasted more than a few weeks and is not improving with rest, a pain specialist assessment can help identify what is driving it.
What Causes Chronic Fatigue Syndrome?
The exact cause of chronic fatigue syndrome has not yet been established. What research has shown is that CFS is more likely to affect women than men, and it is far more common in adults than in children.
Ongoing research points to several factors that may contribute to the onset of CFS, although no single cause has been confirmed:
| Potential Contributing Factor | What Current Research Shows |
|---|---|
| Post-viral trigger | Some people develop CFS-like illness after an infection, including Epstein-Barr virus and, more recently, COVID-19 (often referred to as Long COVID). |
| Immune system changes | Some patients show altered immune responses, including reduced natural killer cell activity, which may contribute to symptom severity. |
| Hormonal and stress-response changes | Some people with CFS have differences in cortisol patterns linked to the body’s stress-response system, which may influence fatigue and inflammation. |
| Family history | CFS has been observed to occur more frequently within some families, suggesting a possible genetic or shared environmental influence. |
How Is Chronic Fatigue Syndrome Diagnosed in Singapore?
There is no single test that confirms chronic fatigue syndrome. At Singapore Paincare, our team of experienced primary care doctors and pain care specialists, together with a rheumatologist, will evaluate your condition through:
- A physical examination
- A mental evaluation
- Detailed questions about your symptoms, including onset, duration, and pattern of fatigue
- A review of your medical history
Additional tests, such as blood or urine tests, may be requested to check for infection and to rule out other illnesses that can cause similar symptoms. Because CFS has no specific diagnostic marker, this process of ruling out other explanations is a standard and necessary part of reaching an accurate diagnosis.
What Are the Treatment Options for Chronic Fatigue Syndrome?
There is no single test that confirms chronic fatigue syndrome. At Singapore Paincare, our team of experienced primary care doctors and pain care specialists, together with a rheumatologist, will evaluate your condition through:
- A physical examination
- A mental evaluation
- Detailed questions about your symptoms, including onset, duration, and pattern of fatigue
- A review of your medical history
Additional tests, such as blood or urine tests, may be requested to check for infection and to rule out other illnesses that can cause similar symptoms. Because CFS has no specific diagnostic marker, this process of ruling out other explanations is a standard and necessary part of reaching an accurate diagnosis.
Who Is Most at Risk of Chronic Fatigue Syndrome?
CFS does not affect everyone equally. Based on available population data:
| Risk Factor | Key Findings |
|---|---|
| Sex | Women are affected substantially more often than men. US national health data (2021–2022) found 1.7% of women had ME/CFS, while prevalence was lower in men. Other studies estimate women are affected 3–5 times more often than men. |
| Age | ME/CFS is far more common in adults than in children. US data shows prevalence increasing from 0.7% among adults aged 18–39 to approximately 2.0–2.1% among those aged 50–69. |
| Overall prevalence | An estimated 1.3% of US adults (around 3.3 million people) had ME/CFS in 2021–2022. Studies from parts of Asia, including Japan and Korea, report prevalence ranging from approximately 0.76% to 1.31%. |
How Can I Prevent Chronic Fatigue Syndrome?
There is currently no known way to prevent chronic fatigue syndrome.






