Health experts are urging the public not to ignore a potentially serious symptom that can manifest during sleep, leaving visible evidence on bed linen by morning. Profuse night sweats that drench pyjamas, sheets, and pillows could be an indicator of several types of cancer.
Understanding the Difference Between Normal and Concerning Sweats
It is common to sweat at night due to factors like a warm room or sharing a bed. However, medical professionals draw a clear line between this and the severe, drenching episodes associated with illness. The NHS defines night sweats as sweating so heavily that your nightclothes and bedding are soaking wet, even when sleeping in a cool environment.
The NHS advises that if you regularly wake up with soaking wet sheets, you should get it checked by a GP. This guidance is echoed by leading charities, which stress the importance of investigating persistent, severe symptoms.
Which Cancers Can Cause Severe Night Sweats?
While night sweats can be caused by infections, medication side effects, or menopause, they are also listed by Cancer Research UK as a general symptom of cancer. The NHS specifies that particular cancers may lead to excessive sweating. These include:
- Leukaemia
- Lymphoma (both Hodgkin and Non-Hodgkin)
- Kidney cancer
- Bone cancer
- Mesothelioma
- Advanced medullary thyroid cancer
- Germ cell tumours
- Carcinoid tumours
- Prostate cancer
Focusing on leukaemia, the charity Leukaemia Care notes that approximately 30% of people diagnosed experience significant night-time perspiration. They describe a specific pattern: "You regularly have night sweats that wake you up at night – you may wake up drenched in sweat, unable to cool down even if your room is cool. Many describe the feeling as if they had just got out of a swimming pool and laid down in bed."
When Should You Definitely Seek Medical Advice?
The key is to recognise when night sweats are part of a broader, unexplained pattern. The NHS recommends booking an appointment with your doctor if your night sweats are accompanied by other worrying signs.
You should see a GP if: you are having night sweats and are also losing weight for no clear reason; if you have a high fever, cough, or diarrhoea; or if the sweats are so regular and severe that they disturb your sleep or cause you concern.
Cancer symptoms vary widely, and while a persistent cough may point to lung cancer or blood in stools to bowel cancer, systemic signs like heavy sweating are easier to dismiss. Experts emphasise that early detection is crucial, so any persistent, unexplained change in your health warrants a professional opinion.
