Night sweats

Category: General & Whole-Body Symptoms · All general symptoms

What it can feel like

Night sweats are episodes of heavy sweating during sleep that soak nightclothes or bedding and are not explained by a warm room or heavy covers. Occasional mild sweating at night is common; drenching, repeated night sweats are the pattern clinicians ask about.

Possible causes

A symptom can have many causes, and most are not serious. The lists below group conditions this symptom can be associated with — common causes first. They are possibilities to discuss with a clinician, not a diagnosis.

Common causes

Night sweats can be associated with a warm sleeping environment, anxiety, alcohol in the evening, and the hormonal changes of the menopause. They can also accompany infections while the body recovers.

Other possible causes

Persistent drenching night sweats can be associated with longer-running infections such as tuberculosis, with thyroid overactivity, with some blood conditions, and occasionally with cancers such as lymphoma — one reason a persistent pattern should be checked.

Red flags — when to seek help promptly

Night sweats together with unexplained weight loss or persistent fever
Night sweats with swollen glands, severe itching or new lumps
Night sweats in someone who has recently travelled to regions where malaria occurs
Night sweats that continue for more than a few weeks

What a clinician may do

A clinician will ask about the pattern, weight changes, fevers, travel and medicines, and examine your glands, thyroid and chest. Blood tests are usual, and a chest X-ray or further tests may follow depending on what the first results show.

Related guides on MedicalVideos.com

Frequently asked questions

Are night sweats always serious?

No — most night sweats have an ordinary explanation such as a warm room, anxiety or the menopause. The pattern that matters is drenching sweats night after night, especially with weight loss or fever, and that pattern should be checked.

Should I keep a record?

Yes — note how often they happen, whether you have fever or weight loss, any new medicines and recent travel. A short record helps your clinician judge which tests, if any, are worthwhile.

Related symptoms — General & Whole-Body Symptoms

Chills Excessive sweating Excessive thirst Fatigue Feeling cold all the time Feeling generally unwell (malaise)

Browse the N section of the A–Z list or return to the Symptoms A–Z hub.

Please note: This page is educational information about a symptom. A symptom alone cannot diagnose any condition, and the causes listed here are possibilities, not a diagnosis. If you are worried about a symptom — especially one that is new, severe, getting worse or not going away — please see your own clinician, who can examine you and arrange tests. In an emergency, call your local emergency number.