Conditions Basics

What are night sweats?

Night sweats are heavy sweating during sleep. This kind of sweating is different than the occasional sweating people have from sleeping deeply, being in a warm room, or having too many blankets.

Night sweats are often so heavy that your clothing and sheets are soaked to the point that you have to change them.

Many women who are in menopause have night sweats. Night sweats can also be related to other health problems.

It's important to see your doctor if you have night sweats that happen often. He or she will want to make sure that your night sweats aren't caused by something serious.

What causes them?

Night sweats can be caused by many things. Possible causes include:

• Your body making too much thyroid hormone.
• Anxiety.
• Too much alcohol.
• Sleep apnea.
• Hormone changes related to menopause.
• Infections. These could include tuberculosis (TB), infection of the heart's valves, or HIV.
• Some cancers, including leukemia and Hodgkin lymphoma.

How are they diagnosed?

Your doctor will ask questions about your sweating and your health history. You may be asked:

• How often you have night sweats and how long they last.
• If you are taking a new medicine.
• If you have other symptoms, such as fever, pain, or unplanned weight loss.

You also will have a complete physical examination. You may have tests, depending on the results of your examination. For example, you might have blood tests or an X-ray to help find the cause of your sweating.

Having night sweats a few times is usually nothing to worry about. But talk to your doctor if you often have night sweats or you have other symptoms along with them. These might include fever, chills, pain, or unplanned weight loss.

You might want to keep a notebook to write down how long the sweating lasts and any other symptoms you have. This may help your doctor find the cause of your sweating.