If you suffer from nightsweats, you probably don't need us to tell you that they can seriously disrupt your sleep.
If you wake up in the night plastered to a soggy bedsheet, even when the weather is cool and you're not bundled under a thick duvet, there might be a health issue to blame.
Below is a list of the most common causes of this uncomfortable and distressing condition.
See also: How to combat insomnia as you get older
See also: Your feet could be the secret to a good night's sleep
It's not just characters in Russian literature who get tuberculosis (TB). The bacterial infection is uncommon but has slowly re-emerged in Europe in recent years (in 2014, more than 6,500 cases of TB were reported in England) – and one of its tell-tale symptom is sweating at night. Other symptoms include a persistent cough that lasts more than three weeks and usually brings up phlegm, which may be bloody, weight loss, high temperature, tiredness and fatigue, loss of appetite and swelling.
Other infections such as endocarditis (inflammation of the heart valves), osteomyelitis (inflammation in the bones), and abscesses can also cause night sweats – as can HIV infection.
The hot flushes that come with the menopause can occur at night and are one of the biggest causes of night sweats in women. The good news is that severe cases can be controlled to a great extent with hormone replacement therapy (HRT) or other treatments.
Low blood sugar can be another cause of excessive perspiration after dark, and diabetes will often be considered by a doctor if night sweats are reported. Other symptoms associated with the condition are shakiness, light-headedness, dizziness, confusion, rapid heartbeat, irritability and extreme hunger.
Obstructive sleep apnoea
Obstructive sleep apnoea is a relatively common condition which sees the walls of the throat relaxing and narrowing during sleep, interrupting normal breathing. Night sweats are often experienced by sufferers – although the primary symptoms are loud snoring, noisy or obstructed breathing and gasping noises. Lifestyle changes are the primary treatment for the condition.
Don't panic. It's quite rare for night sweats to be caused by cancer, but they are an early symptom of some forms of the disease. Notably lymphoma and leukaemia. For this reason it's a good idea to see your GP if you are suffering night sweats, if only so certain things can be ruled out.
There are a number of commonly prescribed medicines that are known to cause night sweats in some patients. These include anti-depressants, aspirin and the steroid prednisolone. Always speak to your doctor before stopping prescribed medication.
Drinking alcohol causes blood vessels to dilate, leading to sweating – even when we don't have a raised body temperature. As well as just having a skinful, night sweats can also be triggered by alcohol intolerance or by withdrawal from alcohol. If you experience frequent night sweats and are a drinker, you should discuss the issue with your GP.