# What are the main symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)? Canonical page: https://clinicsjo.com/en/faq/ma-hi-alaerad-alrayisiyat-limutazimat-altaeb-almuzmin-me-cfs Language: en Category: neurology Publisher: ClinicsJo Published: 2026-09-13T08:09:52.442Z Content updated: 2026-09-13T08:09:52.442Z Translation (ar): https://clinicsjo.com/ar/faq/ma-hi-alaerad-alrayisiyat-limutazimat-altaeb-almuzmin-me-cfs Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex, long-term medical condition affecting multiple body systems, causing significant disability that may prevent individuals from performing usual daily activities, and in some cases, can lead to complete bedridden status [\[1\]](). The main symptoms of this syndrome are central to its diagnosis and include: ## Severe Persistent Fatigue Severe, persistent fatigue is a primary symptom of ME/CFS. This fatigue differs from normal tiredness; it does not improve with rest, persists for six months or longer, and is severe enough to prevent a person from performing activities they were able to do before becoming ill [\[1\]](). It is not the result of unusual or intense exertion [\[3\]](). ## Post-Exertional Malaise (PEM) Post-Exertional Malaise (PEM) is defined as the worsening of symptoms after any physical or mental activity, even if mild [\[1\]](). This malaise can occur after grocery shopping, potentially requiring a nap before returning home, or the person may need assistance to return [\[3\]](). There is no way to predict what will trigger the malaise or how long it will take to recover, which may last for days, weeks, or even longer [\[3\]](). To avoid worsening symptoms, individuals with ME/CFS must carefully balance activity and rest, and keeping a symptom journal may help in learning how to pace activities [\[2\]](). ## Sleep Disorders People with ME/CFS suffer from sleep problems, such as difficulty falling or staying asleep [\[3\]](). Most importantly, a full night's rest does not relieve the fatigue or other symptoms; instead, the person wakes up feeling tired even after sufficient sleep [\[2\]](). ## Cognitive and Orthostatic Intolerance Issues In addition to the primary symptoms, a person must experience one or both of the following to be diagnosed with ME/CFS: - **Problems with thinking and memory:** This includes difficulty concentrating, forgetfulness, and trouble following details, sometimes referred to as "brain fog" [\[3\]](). - **Worsening of symptoms upon standing or sitting upright (Orthostatic Intolerance):** This can cause dizziness, lightheadedness, weakness, or fainting when standing or sitting [\[1\]](). This can occur when the body has difficulty regulating blood pressure and heart rate when changing positions or standing for long periods [\[2\]](). ## Additional Symptoms ME/CFS can also cause a range of other symptoms, which may vary from person to person and change over time [\[1\]](). These include: - Various pains, including muscle and joint pain and headaches [\[1\]](). - Sore throat or painful swollen lymph nodes in the neck or armpits [\[1\]](). - Digestive issues, such as Irritable Bowel Syndrome (IBS) [\[1\]](). - Chills and night sweats [\[1\]](). - Sensitivity to foods, odors, chemicals, light, or noise [\[1\]](). Since there is no specific test to diagnose ME/CFS, doctors rely on excluding other diseases that cause similar symptoms, as well as a comprehensive evaluation of symptoms and medical history [\[1\]](). If you are experiencing severe fatigue or any of these symptoms, it is important to consult a healthcare provider to rule out more serious conditions and receive a proper diagnosis and care. For more information about this syndrome, you may visit [Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Challenging Diagnosis and Daily Management (Arabic)](). ## Medical references - [Myalgic Encephalomyelitis/Chronic Fatigue Syndrome]() - [ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome)]() - [Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)]() General health education; not a substitute for individualized clinical assessment. Citation URL: https://clinicsjo.com/en/faq/ma-hi-alaerad-alrayisiyat-limutazimat-altaeb-almuzmin-me-cfs#answer