Night Sweats – Causes and Treatment

Do you wake up in the night with damp hair or a T-shirt clinging to your body? Have you noticed it happens particularly at certain points in the month? The truth is that the occasional night sweat isn't unusual — especially if you've eaten something spicy before bed, you're wearing thicker pyjamas, or the temperature in your bedroom is high.

Night sweats become a problem when they occur regularly, disrupt your sleep and force you to change your nightwear or even your bedding. If this happens to you often, the causes may be medical — and that's when it's time to speak to a doctor.

In this article, you'll find everything you need to know about night sweats.

What are night sweats

When the room is very warm, you're sleeping in thick clothing or you're under a warm duvet, sweating at night is a normal process through which the body regulates its temperature. Your body releases water and electrolytes, which evaporate through the skin and create a sensation of coolness. This process describes what we call normal sweating — nothing more than a physiological response occasionally triggered by heat or physical exertion.

Excessive sweating during sleep, on the other hand, is usually more intense, occurs repeatedly and can happen even in normal temperature conditions. It's accompanied by discomfort and is frequently linked to poorer sleep quality and night-time restlessness — precisely because the subsequent feeling of cold and the damp bedclothes keep waking you up to change your clothes and sheets. Night sweats of this kind are often associated with hormonal imbalances or other conditions.

When night sweats become a concern

The frequency and intensity of the sweating are the signs you should look out for. If you only sweat at night occasionally and wake up with damp clothing, there's most likely no cause for concern.

Suspicion of a possible health problem arises when night sweats occur daily or very frequently and you have to change your clothes or bedding, or when other warning signs appear such as fever, fatigue, a cough, pain, chills or weight loss.

It's advisable to see a doctor if:

• the symptoms last longer than two weeks;
• the episodes of night sweats come on suddenly and are intense;
• the excessive sweating disrupts your sleep;
• you notice symptoms such as fever, diarrhoea, a cough or other worrying signs;
• the night sweats begin several months or years after menopausal symptoms have resolved.

Possible causes of night sweats

It isn't always possible to pinpoint the exact causes of night sweats, but they usually involve environmental factors, certain health problems, hormonal factors or a combination of these. If you also have other symptoms, these can help narrow down the possible causes and identify any underlying conditions.

Environmental and lifestyle factors

The environment you sleep in — from a high room temperature and poor ventilation to your mattress, bedding and thick clothing — can raise your body temperature overnight and make you sweat.

Everyday habits, particularly your bedtime routine, can also be linked to night sweats. If you suffer from anxiety, you're going through a stressful period, you consume alcohol, caffeine or spicy food before bed, or you exercise intensely in the evening, this could explain why you wake up drenched in sweat.

Hormonal causes of night sweats

Hormonal imbalances and disorders can also be responsible for excessive sweating, including at night. Common hormonal causes of night sweats include:

• Menopause and perimenopause (in women)
• Andropause (in men)
• Pregnancy
• Thyroid disorders (an underactive thyroid, for example)
• Raised cortisol levels (associated with periods of intense stress)

These imbalances are frequently accompanied by symptoms such as unexplained fluctuations in weight and energy levels, headaches, sexual dysfunction and changes to the menstrual cycle.

Medical causes of night sweats

There are cases in which night sweats are linked to conditions such as infections and chronic illnesses — which is precisely why it's important to keep an eye on accompanying symptoms and the overall picture. Medical causes of night sweats in women include:

• Infections such as tuberculosis, HIV or endocarditis (infection of the heart valves)
• Diabetes
• Nocturnal hypoglycaemia (common in patients with type 1 or type 2 diabetes)
• Sleep apnoea (according to research from 2018, women experiencing menopausal night sweats have an 80% higher risk of developing sleep apnoea)
• Autoimmune conditions such as sarcoidosis, Graves' disease and rheumatoid arthritis
• Certain cancers, such as Hodgkin lymphoma
• Neurological disorders (in rare cases)

Side effects of medications that cause night sweats

Certain medications are known to trigger night sweats. If you've recently started a course of treatment and the night-time sweating began shortly afterwards, this could be the cause — in which case it's best to speak to the doctor who prescribed it:

• Painkillers such as aspirin and paracetamol
• Antidepressants
• Steroids (including prednisone and cortisone)
• Hormone treatments
• Diabetes medications
• Fever-reducing medicines
• Beta blockers

Diagnosis and recommended investigations for night sweats

If night sweats are worrying you and you see a doctor to establish the exact cause, they will usually begin with a clinical assessment. You'll discuss your symptoms, medical history and lifestyle in detail, followed by a physical examination.

Depending on the context and accompanying symptoms, further investigations may be required, such as blood tests, tests for infection, ultrasound scans or sleep studies.

Generally, blood tests are recommended to detect any hormonal or metabolic imbalances. These measure blood sugar, thyroid hormones and cortisol levels; a full blood count may also be carried out to reveal possible infections or inflammation in the body. Depending on your symptoms, imaging such as a thyroid or abdominal ultrasound may also be recommended.

To confirm serious infections such as tuberculosis, HIV or viral hepatitis, specific infection tests can be carried out. And if a disorder such as sleep apnoea is suspected, sleep studies can be performed to confirm it.

Treatment and remedies for night sweats

If night sweats occur frequently and disrupt your sleep, your doctor will recommend a tailored treatment based on the cause identified. This treatment usually involves a combination of medical measures and adjustments to environmental or lifestyle factors.

Medical approaches to night sweats

If night sweats are caused by an infection, a metabolic disorder or a hormonal condition, treating that cause takes priority. Your doctor may recommend:

• Specific treatments or therapies for infections and hormonal imbalances.
• A dose adjustment or change of medication if the sweating is a side effect of particular drugs.
• Psychological support for anxiety and chronic stress.

Natural solutions and lifestyle changes for night sweats

Alongside medical treatment, a few seemingly small changes to your sleep environment and lifestyle can help to significantly reduce how often night sweats occur.

The optimal bedroom temperature for more comfortable sleep is between 18 and 20°C. It's also worth using bedding and nightwear made from natural materials such as cotton, which allow the skin to breathe, cutting back on alcohol and caffeine — particularly in the evening — and avoiding spicy meals before bed.

Finally, you can improve your sleep quality by avoiding intense physical exertion for at least 1–2 hours before bedtime, replacing it with relaxation and mindful breathing exercises or a stress-reducing evening routine.

Hormone treatments for night sweats

If hormonal fluctuations are the cause of your night sweats — for example those occurring during menopause in women or andropause in men — your doctor may recommend hormone replacement therapy or natural alternatives containing phytoestrogens, isoflavones or supplements.

The alternatives may be less effective than medication, so it's important to weigh up all the options with a specialist and choose the one best suited to you.

Night sweats in the luteal phase

Hormonal changes linked to night sweats don't occur only during menopause — they can even include the normal fluctuations in oestrogen and progesterone across the menstrual cycle, particularly during the luteal phase.

Some women experience night sweats more frequently before their period, when oestrogen and progesterone levels rise. These fluctuations can raise body temperature and increase sweat gland activity, encouraging heavy sweating at night.

The phenomenon is more common in women going through perimenopause, in women with premenstrual syndrome and in those using hormonal contraception, and it's usually temporary: it eases off at the end of the luteal phase.

Once menstruation begins, however, it's just as important to use period products made from 100% organic cotton, so your skin can breathe and you can enjoy a restful night's sleep — without synthetic components that encourage sweating.

How to prevent night sweats

Preventing night sweats primarily requires good sleep hygiene. Regulate the room temperature, air the room regularly and choose suitable bedding to create a restful environment and reduce night-time discomfort.

Avoid heavy meals and intense physical exertion in the evening, drink plenty of water throughout the day and limit your caffeine and alcohol intake to lower the risk of excessive sweating at night.

Regular medical check-ups, including endocrinological and psychological assessment where necessary, will help you identify and manage the factors that can contribute to night sweats early on.

Frequently asked questions about night sweats (FAQ)

Night sweats don't always have an obvious explanation — especially as episodes can recur at different stages of life while having entirely different causes. Not sure which tests are needed? Still unsure whether you should be worried? We hope you'll find the answers you're looking for below.

Can night sweats be caused by stress?

Yes, chronic stress and anxiety can raise cortisol levels — a hormone involved in regulating body temperature. This mechanism can become a cause of night sweats, particularly if you're going through a tense period and experiencing insomnia and restless sleep.

What tests are carried out for night sweats?

Depending on the accompanying symptoms, your doctor may recommend blood tests measuring blood sugar, TSH, thyroid hormones, cortisol levels, inflammatory markers or a full blood count. In certain cases, additional tests for infections (tuberculosis, HIV, hepatitis), imaging investigations or sleep studies to rule out apnoea may be appropriate.

Can night sweats be linked to anxiety or depression?

Yes, anxiety and depression can affect body temperature regulation and sleep quality; in addition, some medications used to treat these conditions can cause night sweats as a side effect.

Are occasional night sweats dangerous?

Isolated episodes of night sweats — occurring, for example, when the room is too warm, when you're stressed or when you've eaten spicy food before bed — are generally not a cause for concern. Seeing a doctor becomes important when the sweating is frequent or intense, or accompanied by other alarming symptoms.

Which serious illnesses can cause night sweats?

Persistent night sweats combined with fever, unexplained weight loss or marked fatigue may indicate serious infections, autoimmune conditions or certain cancers such as lymphoma, and require medical assessment.

How can I tell hormonal night sweats from pathological ones?

Hormonally driven night sweats often occur cyclically or in specific situations, such as during menopause, perimenopause or the luteal phase of the menstrual cycle. Pathological night sweats tend to be persistent and severe, and are associated with more worrying symptoms such as fever, pain or a persistent cough.

Can night sweats be caused by diabetes or low blood sugar?

Yes, in people with diabetes, nocturnal hypoglycaemia can trigger heavy sweating during sleep. In these cases, monitoring blood sugar and adjusting treatment with your doctor is advisable.

Why do night sweats occur in men after the age of 40?

In men, night sweats may be linked to falling testosterone levels, known as andropause. These hormonal changes can affect temperature regulation and may be accompanied by fatigue, reduced libido and sleep disturbances.

Which natural remedies can reduce night sweats?

Simple measures such as airing the bedroom, maintaining an optimal temperature, wearing nightwear made from natural materials and practising relaxation techniques can reduce the frequency and intensity of night sweats. Some people notice an improvement with herbal preparations — but always speak to a professional before using them.

What role does room temperature play in night sweats?

A high bedroom temperature is one of the most common causes of night sweats, as it makes regulating body temperature more difficult and encourages sweating. Experts recommend a temperature of between 18 and 20°C for restful sleep.

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