If you have chronic fatigue syndrome (CFS), there may be times when your symptoms improve and you'll be able to do many normal, everyday activities.

However, at other times your symptoms may flare up and get worse, affecting your daily life.

And people with severe and very severe CFS will normally find carrying out everyday activities too challenging.

Fatigue

The main symptom of CFS is severe fatigue (exhaustion) following mental or physical activity. This does not go away with sleep or rest, and limits your usual activities.

Fatigue is mental as well as physical. Some people describe it as overwhelming. You may feel that:

• It is a different type of tiredness from what you have experienced before.
• After sleeping you do not feel refreshed.
• It is not due to exhaustion.
• It is not simply a loss of motivation, which people with depression often experience.

Exercising can make symptoms worse. This is called post-exertional malaise, or "payback". The effect of this is sometimes delayed. For example, if you were to play a game of sport, the resulting fatigue may not develop for a few hours afterwards, or even the next day.

Other symptoms

There are other common symptoms as well as fatigue, although most people do not have all of them. They include:

• muscular pain, joint pain and severe headaches
• poor short-term memory and concentration, and difficulty organising your 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
• sore throat 
• sleeping problems, such as insomnia and feeling that sleep is not 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

There is no test for chronic fatigue syndrome (CFS), but there are clear guidelines to help doctors diagnose it.

Many people consult their GP because they think they have CFS, but only a small minority go on to be diagnosed with it.

CFS is not diagnosed in people who simply feel tired all the time. There are other symptoms that help to confirm the diagnosis (see symptoms of CFS for more information).

Your GP will ask you about your medical history and carry out a physical examination. You may have blood tests and scans to rule out other conditions, such as anaemia (not enough red blood cells), an underactive thyroid gland or liver and kidney problems.

NICE guidelines for diagnosing CFS

Guidelines released in 2007 from the National Institute for Health and Clinical Excellence (NICE) state that doctors should consider diagnosing CFS if a person has fatigue and all of the following apply:

• There was a clear starting point.
• It is persistent and/or recurrent.
• It is unexplained by other conditions.
• It substantially reduces the amount of activity you can do.
• It feels worse after physical activity.

The person should also have one or more of these symptoms:

• difficulty sleeping, or insomnia
• muscle or joint pain without inflammation (swelling) 
• headaches 
• painful lymph nodes that are not enlarged
• sore throat 
• poor mental function, such as difficulty thinking
• symptoms getting worse after physical or mental exertion
• feeling unwell or having flu-like symptoms
• dizziness or nausea
• heart palpitations, without heart disease

This diagnosis should be confirmed by a clinician after other conditions have been ruled out and the above symptoms have persisted for four months in an adult and three months in a child or young person.

For more information, read the NICE guidelines on CFS.

There is no cure for chronic fatigue syndrome (CFS) but treatments can help relieve the symptoms.

The effectiveness of treatments depends on how CFS affects you. Early diagnosis, balancing rest with activity, medication to control certain symptoms and self-help measures can all help (see below).

Simply diagnosing CFS and receiving specialist advice about how to deal with it can help.

CFS may last for years. However, many people recover or at least adjust their lifestyle to improve their symptoms.

Treatment programme

The National Institute for Health and Clinical Excellence (NICE) advises that an individual programme of treatment should be offered to you with the aims of:

• maintaining and if possible extending your emotional and physical abilities
• managing the physical and emotional effects of your symptoms 

You may be offered the treatments explained below, but remember: what works for one person may not work for you.

The benefits and risks of each treatment should be explained to you, as some treatments could make your symptoms worse. Both you and the healthcare professional treating you will decide on your treatment programme.

If your symptoms continue to get worse for several days after trying a certain treatment, or if your symptoms are particularly severe, contact the healthcare professional who is treating you. It may be necessary to amend your treatment programme.

Cognitive behavioural therapy

Cognitive behavioural therapy (CBT) is a type of therapy that aims to change the way that you think, feel and behave. CBT helps you realise that your problems are often created by you. It is not the situation itself that is making you unhappy but how you think about it and react to it.

Through talking to a professional therapist, you identify the thoughts and feelings that are causing certain behaviours. Your therapist will help you find ways to change your thought patterns and your behaviour so that you can cope better with the emotional impact of your symptoms.

Ideally, your CBT therapist will have experience in dealing with CFS and treatment will be offered on a one-to-one basis. The treatment will be tailored to your needs and may include some of the following:

• helping you to accept your diagnosis
• challenging any thoughts that could prevent your symptoms improving
• trying to increase your sense of control over your symptoms

See the Health A-Z topic about CBT for more information about this type of treatment.

Graded exercise therapy

Graded exercise therapy (GET) is a structured exercise programme that aims to gradually increase how long you can carry out a physical activity. This will usually involve aerobic exercise (exercise that raises your heart rate) such as swimming or walking. You will have your own exercise programme adapted to your own physical capabilities.

GET should only be carried out by a trained specialist with experience in CFS and, if possible, should be offered on a one-to-one basis. After finding your "baseline" in the exercise (what you can comfortably do already) you will gradually increase:

• the length of time that you do the exercise
• the exercise intensity

As part of your exercise programme, you and your therapist will set goals, such as being able to walk to the shops or carry out some gardening. It may take months for you to achieve these goals but it is very important that you do not to exceed the exercise duration and intensity that has been set for you.

Activity management

Activity management is another aspect of your treatment programme that involves setting individual goals and gradually increasing your activity levels. You may be asked to keep a diary of your current activity and rest periods to establish your baseline. Activities can then be gradually increased in a way that you find manageable.

Medication

Your treatment may also involve taking medication, although this will depend on your symptoms. For information about your medication, see the patient information leaflet that comes with it.

Over-the-counter painkillers can help to ease any muscle and joint pain and headaches you may have. Stronger painkillers can also be prescribed by your GP, although they should only be used on a short-term basis.

If you have chronic (long-term) pain, you may be referred to a pain management clinic. There are about 300 of these across the UK, mostly located in hospitals.

Antidepressants can be useful for people with CFS who are in pain or having trouble sleeping. Amitriptyline is a low-dose tricyclic antidepressant that may be prescribed. Amitriptyline is not suitable for everyone – for example, it may not be suitable if you have a history of heart problems. It can also cause side effects such as:

• a dry mouth
• blurred vision
• dizziness
• drowsiness

Lifestyle advice

As well as these treatments you may find the lifestyle advice below helpful.

Pacing

Pacing is an important way of controlling CFS symptoms. It involves balancing periods of activity with periods of rest.

Pacing means not overdoing it or pushing yourself beyond your limits. If you do, it could slow down your progress in the long-term. Over time, you can gradually increase your periods of activity, while making sure they are balanced with periods of rest.

Learning how to make the most of your energy helps increase the amount that you can do. However, you may need to arrange your daily and weekly activities around when you can be active and when you will need to rest.

If you pace your activities at a level that is right for you, rather than rushing to do as much as possible in a short space of time, you may be able to make steady progress.

Other self-help techniques

The following recommendations may also help:

• Avoid stressful situations.
• Avoid alcohol, caffeine, sugar and sweeteners.
• Avoid other food and drink that you are sensitive to.
• Eat small, regular meals.
• Spend time relaxing.

The cause of chronic fatigue syndrome (CFS) is unknown, but there are several theories.

Some experts think that a viral infection such as glandular fever can trigger the condition. Tiredness is normal after a viral infection, but this does not explain why symptoms persist and get worse in CFS.

Contributing factors

The main factors thought to increase the risk of developing CFS are listed below:

• an inherited genetic susceptibility (it is more common in some families)
• viral infections such as glandular fever, which weaken the immune system
• exhaustion and mental stress
• depression 
• a recent traumatic event, such as bereavement, divorce or redundancy
• childhood trauma

Exacerbating factors

There are a number of factors, which while not thought to be directly connected to CFS, can sometimes make the symptoms of CFS worse or more challenging to live with. These include:

• recurring viral or bacterial infections
• not being active enough, or being too active
• stress 
• poor diet
• being socially isolated or feeling frustrated and depressed