Why Do I Sweat in My Sleep? 6 Causes

• Sweating while you sleep could be a symptom of menopause if you’re of menopausal age.
• It could also be due to an infection like pneumonia, a UTI, the flu, or malaria.
• Drinking alcohol before bed could also cause night sweats because it increases your heart rate.

Night sweats are uncomfortable — you may not be able to sleep through the night or wake up soaked in sweat.

Sweating at night is relatively common and may be a side effect of menopause or certain medications. But in some cases, night sweats can signal a more serious underlying issue like hypoglycemia or an infection.

Here are six reasons you may have night sweats and when you need to see a doctor.

1. Menopause

When you go through menopause, your ovaries start to produce less estrogen, progesterone, and testosterone. These changes, especially the change in estrogen, can trigger hot flashes and night sweats.

This is because decreasing hormone levels causes your internal thermostat, called the hypothalamus, to be more sensitive to slight body temperature changes.

If your hypothalamus detects that you’re too warm, your body may trigger a night sweat or hot flash to make you sweat and cool down.

If your menopause symptoms are severe, your doctor may prescribe you a low dose of estrogen.

2. Certain medications

Some prescription medications can interfere with your body’s internal thermostat and trigger night sweats, including:

If you’ve recently started a new medication and you’re experiencing night sweats, ask your doctor if this may be a possible side effect. They may recommend switching medications or decreasing your dose — but never make these changes on your own without consulting your doctor first.

3. Infections

When you have an infection, your immune system reacts by producing more white blood cells. This process can cause your body temperature to rise and trigger sweating, says Brandon Peters, MD, a board-certified neurologist and sleep physician at Virginia Mason Medical Center.

You may develop fever and night sweats if you have:

NOTE: Night sweats are one of the most common symptoms of tuberculosis, a rare but serious respiratory disease. If you have traveled abroad recently and have symptoms like coughing up blood along with fever, see your doctor to check for tuberculosis.

Along with night sweats, fever may also cause symptoms like:

• Chills
• Shivering or teeth chattering
• Flushed face
• Weakness
• Muscle aches

If your fever lasts longer than a week or goes above 104 °F, see a doctor as soon as possible. They may treat you with acetaminophen or intravenous fluids for dehydration.

4. Hypoglycemia

Hypoglycemia occurs when your blood sugar drops abnormally low. It’s most often linked to

diabetes

, but you can also get it if you have pancreas disease or an eating disorder.

“When blood sugar levels fall too low, then this can activate the release of adrenaline,” says Nesochi Okeke-Igbokwe, MD, an internal medicine physician in private practice.

When this happens, your sweat glands are stimulated, and you start sweating to cool down. This can happen during the day, or at night while you’re sleeping.

Some other signs that you may have hypoglycemia include:

• Feeling irritable or anxious
• Feeling shaky
• Feeling confused
• Fast heartbeat

If your blood sugar is low, you can eat a spoonful of sugar or honey to help balance it out. But if you get hypoglycemia regularly, you should see your doctor to determine the best treatment.

5. Drinking alcohol before bed

Drinking alcohol too close to bedtime can also trigger night sweats, even if you only have one or two drinks. There are a few reasons why alcohol triggers nighttime sweating, including:

1. Alcohol relaxes your airways, which can make it more difficult to breathe. This increased effort can cause your body temperature to rise.

2. Alcohol increases your heart rate, which also raises your body temperature and causes sweating.

3. Because alcohol is a toxin, your body may sweat more to help flush it out of your system.

To avoid night sweats, it’s best to stop drinking alcohol around four hours before you go to bed.

6. Some cancers

Certain types of cancer can cause night sweats as an early symptom, including:

• Leukemia can cause extreme, sheet drenching sweats. Nearly a third of leukemia patients say this was an early symptom before their diagnosis. Some other signs of leukemia are:
  • Weakness or fatigue
  • Unexplained weight loss
  • Nosebleeds
  • Bone pain
  • Frequent infections

• Lymphoma can cause night sweats, along with symptoms like:
  • Fatigue
  • Swollen lymph nodes
  • Frequent infections
  • Easy bruising
  • Unexplained weight loss

If you have any of these symptoms along with night sweats, see your doctor as soon as possible.

Some cancer treatments may also cause night sweats, including:

• Chemotherapy
• Radiation therapy
• Hormone therapy
• Other medications like steroids

When to see a doctor

If your night sweats happen often, or if they’re severe — causing drenched nightclothes or bedding — this is a sign that you should see your doctor, Peters says.

“This is especially true if these occur without clear provocative factors, such as an illness or a warm environment,” says Peters.

A doctor can look at your symptoms, perform blood tests, and give you a physical examination to help diagnose the problem, says Okeke-Igbokwe.

Insider’s takeaway

There are many different reasons you might have night sweats, including drinking alcohol or taking certain medications. However, if you have other symptoms like a high fever or unexplained

weight loss

, this may be a sign of a more serious medical condition like cancer or a bacterial infection.

Having night sweats occasionally may not be an issue, but “if your night sweats have been an ongoing problem, you definitely want to seek medical evaluation,” says Okeke-Igbokwe.