Sleep hyperhidrosis

This is the medical term for sweating during sleep: a form of excessive sweating which occurs during the night.

However, a distinction needs to be made between sweating while asleep and night sweats.

Sweating while asleep or night sweats?

Sweating whilst asleep or ‘sleep hyperhidrosis’is a harmless condition which usually has a genetic or external cause, e.g. your environment and is not something to be unduly worried about.

Night sweats are similar to sleep hyperhidrosis in that they happen while you are asleep, but, they are caused by a medical condition such as the menopause.

Night sweats and hot flushes form part of the many symptoms accompanying the menopause which are a response to falling levels of the female hormone oestrogen at this time. For many women this is one of the most miserable signs of the menopause. But men can also be affected by night sweats. Men undergo a form of ‘male menopause’ or ‘andropause’ in which they too experience a range of symptoms as a response to a drop in hormone levels. In their case it is a reaction to falling testosterone levels. So, it is logical to assume that sweating while asleep and night sweats are one and the same, but there is a slight difference in regard to the cause of these conditions.

It is fair to say that sweating while asleep has a genetic reason, e.g. one of your parents suffers from this condition, or your bedroom is too warm whereas night sweats have a medical cause, e.g. menopause. If you have noticed that you sweat to excess during the night or wake up soaked in sweat then speak to your GP. There may be an underlying condition causing this problem which requires further investigation.

Night sweats

These affect both men and women and occur irrespective of the temperature in your bedroom. They result in you waking up with nightwear and/or bedding drenched in sweat and tired due to a broken night’s sleep.

If this happens over a period of several nights then it leads to extreme tiredness and a sense of feeling less than your best.

Causes of night sweats

These can develop for a variety of reasons which include:

• Diet
• Personal hygiene issues
• Certain foods
• Allergies
• Some prescription medicines such as antibiotics and antidepressants.
• Over the counter medicines, e.g. aspirin
• Stress
• Anxiety
• Depression
• Diseases such as HIV or AIDS
• Diabetes
• Cancer, e.g. Non-Hodgkin Lymphoma
• Acid reflux disease
• Rheumatoid arthritis
• Stroke
• High blood pressure
• Certain neurological conditions, e.g. autonomic neuropathy

Certain lifestyle factors such as alcohol, smoking and drug abuse can also cause night sweats.

Descriptions for the medical conditions mentioned above can be found in our glossary section.

Male night sweats

Men: if you are at a mid life stage and have suddenly developed night sweats then this may be a symptom of the male menopause.

Female night sweats

Women: night sweats, along with mood swings, aches and pains and hot flushes are a normal part of the menopause. This is due to fluctuations in hormone levels and reduced fertility.

Younger women can experience night sweats. Teenage girls and women in their twenties can suffer from excessive sweating which is due to changes in their hormone levels. These changes are dramatic during puberty but usually settle down once they reach adulthood.

Pregnancy is another cause of night sweats which is also due to fluctuating hormones.

Children and night sweats

Night sweats can also occur in children. If you are a parent then try not to worry as there is usually a good reason for this such as wearing pyjamas which are too warm.

Heavy bedding or going to bed after being physically active often leads to night sweats. These are innocuous reasons but there are occasions where night sweats are caused by something more serious such as an illness or disease. Fevers are very common in children and often occur as a result of an infection, e.g. strep throat which cause night sweats. If your child has recently lost weight, is excessively tired and suffers from night sweats then this may be a sign of hyperthyroidism. Hyperthyroidism is the medical name for an overactive thyroid which produces an excess of hormones such as thyroxine.

This causes many of the functions of the body to speed up which manifests itself as a racing heart, brittle hair, anxiety and night sweats.

Other medical conditions include diabetes, tuberculosis and in rare cases, cancer.

If your child continues to experience night sweats in spite of you changing them into light cotton nightwear and bedding, and reducing the temperature in their bedroom then seek medical advice. Do this if you are concerned in any way about your child.

Treatment for night sweats

There are a range of options available to you that include switching to light pyjamas and bedding and placing a fan in your bedroom to lower the temperature. Strong deodorants can help although these are usually available on prescription only. Medication is another option as is a treatment called iontophoresis which uses electrical charges to temporarily reduce your sweat glands.

Avoid spicy and/or fatty foods and caffeine before bed. This also applies to alcohol. Swap to caffeine free versions instead and limit your alcohol intake.

If you are a woman going through the menopause then speak to your GP about treatment for night sweats, hot flushes and other symptoms. This equally applies to men going through the male menopause (andropause).

If you have sleep hyperhidrosis then this is likely to be primary or secondary hyperhidrosis (excessive sweating) which requires further investigation. This is particularly the case in secondary hyperhidrosis which is often the sign of an underlying condition such as diabetes or sleep apnoea.

These types of treatment are discussed in greater detail in our treatment for excessive sweating section.