The short answer
Drenching night sweats can be a symptom of some cancers, such as lymphoma and leukemia, often along with fever and weight loss. Night sweats have many other causes, but persistent, unexplained ones should be checked.
Heavy, drenching night sweats can be a symptom of some cancers.
They can occur with lymphoma and leukemia, often with fever and weight loss.
The combination of night sweats, fever, and weight loss is worth reporting to a doctor.
Many other things cause night sweats, including infections, menopause, and some medicines.
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The full explanation.
The simple version
Sweating a little at night is normal, especially in a warm room. But heavy, drenching night sweats that keep happening — the kind that soak your sheets — can occasionally be a symptom of some cancers, and are worth checking.
What they can signal
Night sweats can occur with lymphoma and leukemia. In lymphoma, doctors watch for a group of symptoms together — fever, night sweats, and unexplained weight loss — sometimes called B symptoms.
Night sweats together with fever and weight loss are worth reporting to a doctor.
Other causes
Night sweats are common and usually not cancer. Infections, menopause, low blood sugar, anxiety, and some medicines can all cause them. A doctor can help find the cause.
When to see a doctor
See a doctor for heavy night sweats that keep happening with no clear cause, especially with fever, unexplained weight loss, or swollen lymph nodes.
Words to know
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Common questions
▸When are night sweats a concern?
Occasional sweating is normal, but heavy, drenching night sweats that soak the sheets and keep happening are worth checking, especially with fever or weight loss.
▸Which cancers cause night sweats?
Night sweats can occur with lymphoma and leukemia. In lymphoma, they are one of a group of symptoms — along with fever and weight loss — that doctors pay attention to.
▸What else causes night sweats?
Many things, including infections, menopause, low blood sugar, anxiety, and some medicines. A doctor can help find the cause.
▸When should I see a doctor?
See a doctor for heavy night sweats that keep happening with no clear cause, especially if you also have fever, unexplained weight loss, or swollen lymph nodes.
Questions to ask your doctor
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