Symptoms of ME/CFS are:

• Debilitating fatigue that is worsened by activity, is not a result of excessive cognitive, physical, emotional, or social exertion, and is not significantly relieved by rest.
• Worsening of symptoms after activity (post-exertional malaise) can be delayed in onset, is disproportionate to the activity, and has a prolonged recovery time.
• Unrefreshing sleep, and/or sleep disturbance, which may include flu-like symptoms.
• Cognitive impairment (‘brain fog’), such as difficulty finding words, problems with memory, difficulty concentrating etc.

To suspect ME/CFS, these symptoms should be lasting over 4 months for an adult and 3 months for children.

Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome: diagnosis and management, NICE, 2021

To receive an ME/CFS diagnosis, you would go through a medical assessment to exclude other conditions that may cause these symptoms, for example, inflammatory conditions such as rheumatoid arthritis and lupus, neurological conditions, such as multiple sclerosis, sleep disorders such as insomnia & narcolepsy, endocrine conditions such as thyroid dysfunction, mental health conditions such as depression, anxiety, bipolar disorder, anaemia, or active infectious diseases such as Lyme’s, HIV.

In addition to the above symptoms, people with ME/CFS also usually experience muscle and/or joint pain, increased sensitivity to temperature, light, sound touch, intolerance to alcohol or other food, flu-like symptoms.

No two ME/CFS patients will have the same symptoms and prognosis. While some people may make a full recovery, most patients with ME/CFS would need to adapt their lives to manage their condition in the long-term. Therefore, flare-ups are expected, and the severity of symptoms may fluctuate at any given time.