Quick answer. Most night sweats are caused by menopause, infections, anxiety, or medications and are not serious. Drenching night sweats with weight loss, fever, or new lumps can signal lymphoma, tuberculosis, or other serious illness and should be assessed by a doctor.
Night sweats are repeated episodes of heavy sweating during sleep that soak through nightclothes or bedding, beyond what is explained by a warm room. They are common and usually have a harmless cause.
This guide outlines the common causes, the warning signs that need medical attention, and which specialists to see.
At a glance
| Cause or pattern | What it may suggest | Urgency |
|---|---|---|
| Night sweats with hot flushes in midlife women | Menopause or perimenopause | See a doctor if troublesome |
| Sweats with fever, cough, or feeling unwell | Infection (including tuberculosis) | See a doctor for assessment |
| Sweats linked to stress, anxiety, or a new medication | Anxiety or medication side effect | Discuss with your doctor |
| Drenching sweats with weight loss, fever, or new lumps | Possible lymphoma, TB, or other serious illness | See a doctor promptly |
| Sweats with shakiness or hunger in someone on diabetes treatment | Possible low blood sugar (hypoglycaemia) | Address promptly; review with doctor |
Red flags: when to seek care
See a doctor promptly if your night sweats are persistent or come with any of these warning signs:
- Drenching night sweats that soak bedding, especially if they keep recurring
- Unintentional weight loss
- Persistent or recurring fever
- New lumps or swollen glands (neck, armpit, or groin)
- A persistent cough, coughing up blood, or breathlessness (possible tuberculosis)
- Unusual tiredness, itching, or easy bruising
This combination can signal lymphoma, tuberculosis, or other serious illness and needs assessment. Seek emergency care (call 995 in Singapore) if you also have severe breathlessness, confusion, or a very high fever with feeling extremely unwell.
Common causes of night sweats
Most night sweats are benign:
- Menopause and perimenopause: hot flushes and night sweats are very common in midlife women
- Infections: from common viral illnesses to more serious infections such as tuberculosis
- Anxiety and stress
- Medications: some antidepressants, hormone treatments, and others
- Low blood sugar (hypoglycaemia): especially in people on diabetes medication
- An overly warm bedroom or heavy bedding
Serious causes to exclude
Less commonly, persistent night sweats reflect a serious underlying condition that needs investigation:
- Lymphoma and some other cancers – typically with weight loss, fever, and swollen glands
- Tuberculosis (TB) and other chronic infections
- Overactive thyroid (hyperthyroidism)
- Hormonal conditions
A doctor can arrange blood tests, imaging, or other investigations to look for these.
Self-care and when it is not enough
For mild night sweats without red flags, simple measures may help:
- Keep the bedroom cool and use light, breathable bedding and nightwear
- Avoid alcohol, caffeine, and spicy food close to bedtime
- Manage stress and practise good sleep habits
However, do not rely on self-care if you have any warning sign such as weight loss, fever, or lumps. See a doctor for assessment instead.
Which specialist should you see?
Start with your GP, who can assess your symptoms and arrange initial tests. Depending on the likely cause, you may be referred onward: to a cancer specialist if lymphoma or another malignancy is suspected, or to an endocrinologist for hormonal causes such as thyroid disease or menopause-related concerns.
You can find experienced cancer specialists and endocrinologists in Singapore through our directory.
What to expect at the appointment
Your doctor will start by asking detailed questions: how often the sweats occur, whether they soak your bedclothes, when they began, and whether you have other symptoms such as fever, weight loss, cough, lumps, palpitations or low mood. They will ask about your medications, alcohol intake, and, for women, your menstrual pattern and menopausal symptoms. A physical examination usually includes checking your temperature and feeling for enlarged lymph nodes in the neck, armpits and groin. Depending on the findings, you may be offered blood tests (such as a full blood count, thyroid function and inflammatory markers), and sometimes a chest X-ray or other imaging if infection such as tuberculosis is being considered.
How to prepare
Keeping a brief symptom diary for one to two weeks before your visit is genuinely useful. Record how often the sweats happen, how severe they are, and anything that seems to trigger them. Note your weight if you have a way to track it, any fevers, and the names of all medications and supplements you take, including those bought over the counter. If you have travelled recently or have had contact with anyone with a long-lasting cough, mention this, as it is relevant to infections such as tuberculosis.
Self-management at home
For mild night sweats without warning signs, simple measures often help. Keep the bedroom cool and well ventilated, choose light, breathable cotton bedding and nightwear, and keep a glass of water by the bed. Reducing alcohol, caffeine and spicy food in the evening can lessen episodes, as can a regular, relaxing bedtime routine to ease stress and anxiety. If you suspect a medication is responsible, do not stop it on your own; raise it with your doctor or pharmacist, who can review whether an alternative is suitable.
Special situations
Women in midlife very commonly experience night sweats as part of perimenopause and menopause; these are usually benign but can be discussed if they disrupt sleep. In people taking diabetes medication, sweats accompanied by shakiness, hunger or confusion may signal low blood sugar and should be reviewed, as the treatment may need adjusting. New, persistent or drenching night sweats in anyone should not be ignored.
Common questions
Are occasional night sweats a sign of cancer?
Usually not. Most night sweats are caused by a warm room, menopause, infection, anxiety or medication. It is the combination of drenching sweats with weight loss, persistent fever or new lumps that warrants prompt assessment.
How long should I wait before seeing a doctor?
See a doctor sooner rather than later if sweats are persistent, recurrent or come with any warning sign. Brief sweats during a passing illness or a hot night usually settle on their own.
Related guides
- Best Oncology Clinics in Singapore — our editorial shortlist
- oncology clinics directory
- Constipation
- Bloating
- Leg pain on walking
Sources
- HealthHub (Singapore) – Menopause
- NHS – Night sweats
- Mayo Clinic – Night sweats
- National Cancer Centre Singapore (NCCS) – Lymphoma
Part of our General health & screening guides · Browse all health topics