The exact cause of CFS isn't known, but current thinking is that it may be triggered by any of the following: a viral or bacterial illness; immune system problems; hormone imbalance; stress or emotional trauma.
Breakthrough research from Queensland scientists in 2016 revealed that people with CFS have a defective cell receptor. Scientists hope this could lead to developing a test for CFS, and suggests the cause is physical rather than psychological. The ME Association says other triggers may include an accident or surgery, though the onset of symptoms is sometimes slower and more insidious.
The main symptom of CFS is of overwhelming fatigue that stops you living a normal life. Other symptoms include: joint pain; poor concentration and memory; enlarged lymph nodes; headaches; recurrent sore throat and general flu-like symptoms; difficulty sleeping; night sweats; and digestive problems, such as Irritable Bowel Syndrome (IBS).
Symptoms can be mild through to severe and there are different patterns for how long CFS lasts and how it affects people. Some people have severe symptoms and then recover enough to live normally; others have symptoms that flare up and then go into remission but return again; some suffer symptoms that never go away. Those worst affected have persistent symptoms that continue to get worse.
For a long time, controversy surrounded CFS/ME, with some querying whether it was a real medical condition or not, but it is now recognised by the World Health Organisation and the Royal Colleges of Physicians, Psychiatrists and General Practitioners.
A CFS diagnosis may be made if your symptoms have persisted for four months or longer or are recurrent, had a specific onset (not lifelong), and have resulted in you reducing your activity. Guidance specifies you must also have had one or more of the following symptoms: sleep problems; muscle or joint pain; headaches; painful lymph nodes; sore throat and flu-like symptoms; cognitive dysfunction; feeling worse after physical or mental exertion; dizziness; nausea; palpitations.
Your GP may order a full blood count including tests for inflammatory markers in the blood; thyroid function; blood glucose; and coeliac, renal and liver function tests.
Who gets CFS?
CFS can affect anyone, but it's more common in women, amongst those in lower socio-economic classes and people who have other physical and mental health complaints. The most common age for it to develop is between the early 20s and mid 40s. In children, CFS is most likely to develop in the mid-teens (13-15).
Unfortunately, there's no cure for CFS but symptoms can be managed. Guidelines say you should aim to get a balance between sleep and rest, eat a healthy diet and tackle any underlying health issues such as chronic pain, depression and stress. Counselling and cognitive behavioural therapy (CBT) – a 'talking' therapy – may also help.
Structured exercise programmes may be recommended in some cases. One large review concluded CFS patients generally benefit and feel less fatigued after exercise therapy.
The British Dietetic Association advises CFS sufferers eat a balanced diet (avoiding processed food), with a regular intake of low GI (glycaemic index) foods which slowly release energy. A study in The Journal of the Royal Society of Medicine found people with CFS had low levels of vitamin B (particularly B6). Foods rich in vitamin B6 include wild salmon, bananas, sweet potatoes and cooked spinach. Vitamin B6 is also known to help support infection-fighting T cells.
Vitamin B12 helps improve mood and cognitive function. Foods rich in B12 include lamb, cottage cheese, tuna, shellfish and eggs, but as most of these are animal derived, vegans may be low in this nutrient.
Other nutrients shown to play a role in helping CFS symptoms include magnesium (found in pumpkin seeds, almonds, yogurt, avocados and dark chocolate) and potassium which helps prevent fatigue, irritability and muscles cramps (find it in bananas, dried apricots, and mushrooms).