Sweats and Flushes

Some people with fibromyalgia or ME/CFS (myalgic encephalomyelitis, also known as chronic fatigue syndrome) experience excessive sweating, hot sensations or difficulty tolerating changes in temperature. Episodes can come on with little warning, last a few minutes or much longer, and then fade. The unpredictability can make daily activities difficult to plan.

Why temperature control can be affected

The autonomic nervous system controls automatic functions such as sweating, heart rate, blood pressure and temperature. Problems with autonomic function have been reported in both conditions and may contribute to some people's symptoms. The reasons for sweats and flushes are not fully understood.

In practice, you may feel hot when others in the room feel cold, or shiver when they are comfortable. You may feel unusually hot or cold even when your measured temperature is normal. Some people also become more sensitive to heat, cold or changes in the weather. The NHS information on ME/CFS includes problems controlling body temperature among possible symptoms, and the NHS information on fibromyalgia also recognises difficulties regulating temperature.

Do not automatically attribute a new fever to fibromyalgia or ME/CFS. A raised measured temperature is a fever whatever the cause, and an unusually low reading should not be ignored either.

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Sweating at night and disturbed sleep

For some people, sweating is particularly disruptive at night. Night sweats usually means soaking your nightclothes or bedding even though the room is cool, rather than simply being too warm under a duvet. You may need to change your clothes or sheets, and getting back to sleep can be hard.

Poor sleep tends to make both conditions worse, adding to fatigue, pain and difficulty concentrating the next day. Sweating during the day can be tiring too, and some people feel self-conscious about it at work or in public.

Your situation may be slightly different. ask a question below ↓ and our editorial team will reply with our advice.

Practical ways to cope

What helps depends partly on the cause. If something such as perimenopause, menopause, a medicine or thyroid disease is found to be responsible, treating it may help. Alongside that, these steps can make episodes easier to manage:

• wearing light layers that can be added or removed quickly
• choosing breathable or moisture-wicking fabrics for clothes and bedding
• using several thin blankets at night rather than one heavy duvet, so you can adjust easily
• keeping a fan, a glass of water and a spare set of nightclothes by the bed
• keeping the bedroom cool and well ventilated
• avoiding overheating and drinking regularly, particularly if you sweat heavily
• carrying a small fan, water bottle or spare top when you go out
• noticing possible triggers, such as hot drinks, alcohol, spicy food, caffeine or stress, and cutting back if this seems to help

A simple diary kept for a few weeks can help you spot patterns and is useful to take to a GP appointment.

For people with ME/CFS, staying within individual energy limits may help reduce symptom flare-ups. The NICE guideline on ME/CFS (NG206) recommends personalised energy management covering physical, mental, emotional and social activity. It is not a cure, and its effect on sweating specifically is uncertain. If you share a bed, separate covers or an agreed room temperature can help you both sleep better.

When to speak to your GP

Sweating is not always caused by fibromyalgia or ME/CFS. Other possible causes include perimenopause and menopause, an overactive thyroid, infections, anxiety and some medicines, such as certain antidepressants and opioid painkillers. Low blood sugar can also cause sweating, particularly in people taking insulin or certain diabetes medicines. Mention new or changing symptoms to your GP rather than assuming they are part of an existing diagnosis.

See a GP if sweating is regular, getting worse, affecting your daily life or worrying you, or if you repeatedly wake with soaked nightclothes or bedding. Palpitations or dizziness when standing up are also worth mentioning, as they may help guide assessment. Get advice promptly if sweats come with unexplained weight loss, a high temperature, swollen glands that do not go away or a persistent cough.

If you need urgent advice, use the urgent care service for your part of the UK. Call 999 if sudden sweating comes with chest pain, severe breathlessness or collapse.

Your GP may review your medicines, including any recent dose changes or withdrawal effects, arrange blood tests or refer you to a specialist. If a medicine seems to be the cause, do not stop it suddenly without advice.

The NHS website also has a page on night sweats. Fibromyalgia Action UK and the ME Association provide information about living with these conditions. Check their websites for current details of the support each one offers.

The Next Step

Now that you have read through the advice above, you might want to put it into practice. Our Flare Up Analyser lets you describe your current flare up and we will help you identify likely triggers and what might ease it. Try it now →