Why do I Wake With Night Sweats and Poor Sleep?
Waking up sweating can be caused by a warm bedroom, menopause, anxiety, medicines, alcohol or an underlying medical condition. Obstructive sleep apnoea is another possibility, particularly if you also snore, wake gasping or feel unrefreshed during the day. The pattern and accompanying symptoms help a clinician decide what to investigate.
If you regularly wake drenched in sweat despite a cool room, or sweating repeatedly interrupts your sleep, arrange a GP appointment. Seek assessment sooner if you also have a persistent cough, unexplained weight loss, fever or swollen glands.
What counts as night sweats?
Some sweating during sleep is normal when your room, clothing or duvet makes you too hot. The NHS describes night sweats as sweating that soaks your nightclothes or bedding even though the sleeping environment is cool.
For an assessment, it helps to describe whether your skin is slightly damp or whether you need to change your clothes or sheets. Also note how often it happens. Feeling hot without sweating is a different symptom, although it can still disturb sleep and deserves attention if it persists.
Common causes of sweating at night
A bedroom or bed that is too warm
Heavy bedding, thick sleepwear or an overheated room can make you sweat. If lighter covers and better ventilation resolve the problem and you otherwise feel well, overheating is a plausible explanation. Continued drenching sweats in a cool room need a wider assessment.
Perimenopause and menopause
Hot flushes can happen during sleep, causing sweating and waking. They often affect the face, neck and chest and may be followed by feeling cold. Changing periods, daytime flushes or other menopausal symptoms can help identify the pattern. Night sweats can continue after periods have stopped.
If they affect your sleep, discuss menopause treatment options with your GP. These may include hormone replacement therapy (HRT), where suitable, and menopause-specific cognitive behavioural therapy (CBT). New sweats after a long symptom-free interval should still be assessed.
Anxiety and stress
Anxiety can trigger sweating and make it harder to settle back to sleep. A racing heart or waking with a sense of panic may be part of the picture. However, anxiety should not automatically be assumed to explain repeated drenching episodes, particularly when there are other physical symptoms.
Medicines and alcohol
Some antidepressants, steroids and painkillers can cause sweating. Tell your GP about new prescriptions, dose changes, supplements and any recent reduction or stopping of medicines. A prescriber can review whether treatment is contributing; do not stop prescribed medicines abruptly yourself.
Alcohol can also contribute to sweating and disturbed sleep. If you are dependent on alcohol, seek medical advice before reducing or stopping, because withdrawal can be dangerous.
Low blood sugar
Night-time hypoglycaemia mainly affects people using insulin or certain other diabetes medicines. Sweating may occur with shaking, hunger, palpitations or confusion. Low blood sugar is uncommon in people without diabetes.
If you have diabetes and suspect a hypo, check your glucose if possible and follow your agreed treatment plan immediately. The NHS advice on treating low blood sugar explains what to do. Report overnight episodes to your diabetes team so they can review your treatment.
An overactive thyroid
An overactive thyroid can cause excessive sweating, heat intolerance, palpitations, trembling, weight loss and difficulty sleeping. Thyroid blood tests can help investigate this pattern. Sweating and insomnia can also occur if a levothyroxine dose is too high, so mention thyroid treatment during your medication review.
Infections and other illnesses
Fever during an infection can cause sweating. Persistent sweats with a cough, weight loss or ongoing illness need assessment. Tuberculosis (TB) is one possible cause of a prolonged cough with night sweats, particularly when there has been relevant exposure or travel. These symptoms do not establish the diagnosis.
Other causes include excessive sweating conditions and, less commonly, illnesses such as lymphoma. A clinician considers the whole picture, including examination findings, rather than using sweating alone to identify a serious disease.
Could sleep apnoea explain night sweats and poor sleep?
Yes, there is an association. In obstructive sleep apnoea (OSA), the upper airway repeatedly narrows or closes during sleep. These breathing disturbances can interrupt sleep, sometimes without you remembering an awakening.
A cohort study of night sweats and sleep apnoea found that frequent sweating was more common in untreated OSA and became less common among people using positive airway pressure treatment consistently. This supports considering OSA, but sweating alone cannot diagnose it or predict whether treatment will resolve your symptoms.
A sleep assessment is particularly worth discussing if you also have:
- Regular loud snoring or breathing pauses noticed by a partner.
- Waking with gasping, choking or repeated unexplained awakenings.
- Unrefreshing sleep, morning headaches or excessive daytime sleepiness.
Read more about sleep apnoea, poor sleep and daytime tiredness. When OSA is suspected, a sleep study is usually needed and can often be done at home. Do not drive if excessive sleepiness affects, or is likely to affect, your driving.
Why can I wake drenched in sweat but feel cold?
Sweat evaporation cools the skin, and wet clothing or bedding can leave you feeling chilled after sweating. Menopausal hot flushes can also end with a cold sensation. Feeling cold afterwards does not, by itself, reveal the cause.
If you have shaking chills, feel markedly unwell or have other symptoms, seek medical advice. If you use diabetes medicines, consider whether the episode could be a hypo and follow your diabetes plan. Cold sweats accompanied by chest pain or severe breathing difficulty require emergency help.
When should night sweats be checked?
Book a GP appointment if sweats keep waking you, repeatedly soak your clothes or bedding, or remain unexplained. You do not need to wait until they happen every night.
Tell your GP about unexplained weight loss, persistent fever, swollen glands, widespread itching, a cough that does not settle, or unusual fatigue. A cough lasting more than three weeks with night sweats deserves assessment. New symptoms after a period of recovery also need review.
Seek urgent help if you feel acutely unwell. Contact NHS 111 for urgent advice when you cannot reach your GP. Call 999 for severe breathing difficulty, sudden confusion, collapse, or chest pain accompanied by sweating, nausea or breathlessness. These symptoms need assessment regardless of whether cancer, infection or sleep apnoea is suspected.
How can I reduce night sweats and sleep better?
Start with practical changes while arranging assessment when needed:
- Keep your bedroom comfortably cool and ventilated. Try lighter bedding and loose, breathable sleepwear.
- Change damp clothes or bedding so you are comfortable enough to return to sleep.
- Notice whether alcohol, caffeine or spicy meals trigger episodes, especially if you have hot flushes. Adjust identifiable triggers rather than following a restrictive diet.
- Keep regular sleeping and waking times and allow time to unwind before bed.
- Keep a brief record of sweating episodes, medicines, alcohol, temperature symptoms and how you feel the next day.
Cooling the room may ease discomfort, but it will not treat an underlying thyroid problem, infection or sleep disorder. Treatment works best when it addresses the cause. If insomnia continues after the sweating improves, ask about treatment for insomnia, including cognitive behavioural therapy for insomnia (CBT-I).
Avoid starting sleeping tablets to get through unexplained awakenings without medical advice. They can worsen breathing in some people with sleep apnoea.
What tests might a doctor arrange?
The starting point is your history and examination. Your doctor may ask about the duration and severity of sweating, daytime symptoms, menopause, medicines, diabetes, travel and possible infection exposure. Snoring and witnessed breathing pauses are relevant even if sweating is your main concern.
Depending on the findings, investigations may include a full blood count, inflammatory markers, thyroid function and blood glucose testing. A chest X-ray or infection tests may be appropriate when there are respiratory symptoms or other clinical clues. Suspected sleep apnoea is investigated with a sleep study.
There is no single blood test for all causes of night sweats, and not everyone needs every test. If initial results are reassuring but symptoms continue or change, ask about follow-up.
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Frequently asked questions
Can stress cause night sweats?
Yes. Anxiety and stress can cause sweating and disturbed sleep. However, repeated soaking sweats should not be attributed to stress without considering medicines, hormones, sleep disorders and other symptoms. Your GP can help assess the pattern.
Why do women sweat around the neck and chest at night?
Menopausal hot flushes commonly affect the face, neck and chest. Bedding and clothing can also trap heat in these areas. Where you sweat does not confirm the cause. Mention changing periods, daytime flushes and any other symptoms when seeking advice.
Why do men get night sweats?
Men can have night sweats from overheating, anxiety, medicines, alcohol, low blood sugar, infection or sleep apnoea. The approach is to identify the cause rather than choose a general remedy for male night sweats. Repeated unexplained episodes need assessment.
Can you have night sweats without a fever?
Yes. Menopause, anxiety, medicine effects and sleep apnoea can occur without fever. A normal temperature does not explain the sweating or exclude every medical cause, so persistent episodes still deserve attention.
Are night sweats a sign of cancer?
They can occur with cancers such as lymphoma, but night sweats have many other causes and are not a cancer diagnosis. Repeated drenching sweats with unexplained weight loss, persistent swollen glands, fever or ongoing itching should be checked by a GP.
Why am I tired as well as sweating at night?
Repeated waking can leave you tired, while a condition such as menopause, sleep apnoea, infection or thyroid disease may contribute to both symptoms. Tell your doctor whether you feel exhausted or are actually dozing off unintentionally, as this helps guide the assessment.
Consultant Respiratory Physician practising in London and Surrey, and Senior Physician in Respiratory Medicine at Kingston and Richmond NHS Foundation Trust.
He graduated from Cambridge and completed his doctorate at Columbia University, New York. He is a Fellow of the Royal College of Physicians and President of the Cambridge Medical Graduates’ Society.
MA MB BChir MD (Cantab) FRCP · GMC 4117379 · Book an appointment