There may be times when your symptoms improve and you'll be able to do many normal everyday activities. At other times, symptoms may flare up and get worse, affecting your daily life.

Fatigue
The main symptom of CFS is persistent physical and mental fatigue. This doesn't go away with sleep or rest and limits your usual activities. Most people with CFS describe this fatigue as overwhelming and a different type of tiredness from what they've experienced before. Exercising can make symptoms worse. This is called post-exertional malaise. The effect of this is sometimes delayed – for example, if you were to play a game of sport, the resulting fatigue may not develop until a few hours afterwards, or even the next day. People with severe CFS are unable to do any activities themselves or can only carry out simple daily tasks, such as brushing their teeth. They're sometimes confined to their bed and are often unable to leave their house.

Other symptoms
-- sleeping problems, such as insomnia and feeling that sleep isn't refreshing
-- sensitivity or intolerance to light, loud noise, alcohol and certain foods
-- psychological difficulties, such as depression, irritability and panic attacks
-- less common symptoms, such as dizziness, excess sweating, balance problems and difficulty controlling body temperature
-- muscular pain, joint pain and severe headaches
-- poor short-term memory and concentration, and difficulty organising thoughts and finding the right words ("brain fog")
-- painful lymph nodes (small glands of the immune system)
-- stomach pain and other problems similar to irritable bowel syndrome, such as bloating, constipation, diarrhoea and nausea