The main symptom of myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS), is feeling extremely tired and generally unwell.

Symptoms vary from person to person, and the severity of symptoms can vary from day to day, or even within a day.

Extreme tiredness (fatigue)

The main symptom of ME/CFS is extreme physical and mental tiredness (fatigue) that does not go away with rest or sleep. This can make it difficult to carry out everyday tasks and activities.

Most people with ME/CFS describe their fatigue as overwhelming and a different type of tiredness from what they've experienced before.

Exercising usually makes the symptoms worse. Sometimes the effect is delayed and you'll feel very tired a few hours after you've exercised, or even the next day.

Problems sleeping

Many people with ME/CFS also have problems with their sleep.

You may find that:

Problems with thinking, memory and concentration

If you have ME/CFS, it's also common to have:

These problems are sometimes described "brain fog".

Other symptoms

Other symptoms of ME/CFS can include:

Severity of symptoms

Most cases of ME/CFS are mild or moderate, but 1 in 4 people have severe symptoms. If your symptoms are severe, a specialist should be involved in your treatment.

ME/CFS symptoms can be considered:

There may be times when your symptoms get worse. These periods are known as relapses.

What else could it be?

The symptoms of ME/CFS are similar to those of other conditions.

If you think you may have ME/CFS it's important to see a GP to make sure you get a correct diagnosis. A GP should also be able to refer you to a ME/CFS specialist if they think it would help you.