Why Do We Sweat While Sleeping?

If you've ever awakened drenched in sweat, you might wonder what causes sweating while sleeping. If it occurs repeatedly, it may be associated with other medical conditions and may require further evaluation. Night sweats also may mean different things to different people, such as children or women going through menopause.

Less Serious Causes

While some causes of night sweats may be serious, many common ones are not. These include:

• Sleep environment
• Anxiety and nightmares
• Hormones
• Gastroesophageal reflux disease (GERD)
• Alcohol consumption

Sleep Environment

One of the most common reasons you might get sweaty at night is because you're trying to sleep in a warm or hot sleep environment. If your bedroom thermostat is cranked up, you're wearing heavy fleece pajamas, you're buried under blankets and comforters, or you don't have air conditioning, it’s normal if you get too warm and sweat.

Also, your body goes through normal temperature variations throughout sleep. Most people's core body temperature dips towards morning, often around 4 a.m. Moreover, during certain phases of sleep, the autonomic nervous system (which controls body temperature, heart rate, blood pressure, and other factors) may become revved up and lead to some sweating.

Anxiety and Nightmares

Nightmares and generalized anxiety may provoke panic attacks during sleep, which can lead to sweating. If you have recurrent bad dreams, and especially if you have post-traumatic stress disorder (PTSD), getting treatment may be helpful for stopping your night sweats (and alleviating other, more serious symptoms, as well).

In addition, children may become sweaty while experiencing night terrors. Other symptoms include:

• Thrashing around
• Fast breathing and heartbeat
• Screaming
• Acting upset

Hormones

Someone going through perimenopause (the "change" before menstruation ends) may have an increased incidence of hot flushes (or flashes) during sleep. In general, postmenopausal women report poorer sleep quality than premenopausal women because of insomnia caused by night sweats and hot flashes.

Interestingly, the risk of developing obstructive sleep apnea (OSA) increases significantly in menopause due to the loss of the hormones estrogen and progesterone. Therefore, night sweats in older women may occur with menopause as a result of sleep apnea.

GERD

While not among the most prevalent symptoms of gastroesophageal reflux disease (GERD), night sweats are becoming more recognized in association with this condition. Your sleep sweat could be related to GERD if you have other symptoms such as:

• Heartburn
• Chest pain
• Vomiting
• Hoarse voice

If GERD is the cause, treatment for the condition should help alleviate night sweats.

Alcohol Consumption

Some people notice they get sweatier in sleep after drinking alcohol. Alcohol dependency, in particular, may cause sweating at night.

Alcohol is a muscle relaxant that can affect the upper airway and worsen snoring and sleep apnea. Therefore, the consumption of alcohol may be linked to night sweats through sleep-disordered breathing like apnea.

More Serious Causes

Sometimes, sweating while sleeping is a symptom that helps point to a serious condition that needs to be treated. Conditions related to night sweats include:

• Sleep apnea
• Infection
• Autoimmune disorders
• Some cancers

Sleep Apnea

Sleep apnea involves pauses in breathing during sleep that wake you up or bring you into a lighter stage of sleep. This condition makes you struggle to breathe, which means your body is exerting itself—possibly enough to make you sweat. Other symptoms to watch for include:

• Excessive daytime sleepiness
• Difficulty concentrating
• Waking up with a dry mouth, sore throat, or headache
• Loud snoring
• Awakening with a gasp
• Bed partner reporting that you stop breathing periodically, then snort and gasp

Sleep apnea is a dangerous condition. Not only can it increase the odds that you'll fall asleep or be inattentive while driving or working, but it also increases your risk of heart attack and stroke.

Treating sleep apnea, which is usually done with a continuous positive airway pressure (CPAP) machine, typically helps alleviate night sweats as well as other symptoms.

Infections

Some serious infections can cause night sweats, including:

• Tuberculosis
• Brucellosis
• Bacterial infections
• HIV

See your doctor if you also have other symptoms that suggest an infection, such as:

• Fever
• Chills
• Body aches
• General weakness
• Fatigue
• Sore throat or cough
• Lack of appetite
• Diarrhea
• Vomiting
• Unintended weight loss

Treating the infection should bring you relief from symptoms, including night sweats.

Autoimmune Disorders

In autoimmune diseases, your immune system mistakes a normal part of your body for a dangerous pathogen, like a virus or bacterium, and tries to destroy it. Some of them can cause excessive sweating, including nighttime sweating, such as:

• Graves' disease
• Sarcoidosis
• Rheumatoid arthritis

This symptom could be related to fevers, which are a common symptom, and they may contribute to the fatigue that's common in people with autoimmune disorders. While symptoms vary from one condition to another, other common symptoms of autoimmunity include:

• Inflammation with redness and heat
• Muscle aches
• Joint pain
• Flares (periods of heightened symptoms) and remissions (periods of lighter symptoms)

Some Cancers

Some types of cancer, especially Hodgkin's lymphoma, can cause drenching night sweats. However, this cancer is typically accompanied by other symptoms, which may include:

• Persistent, painless swelling in the lymph nodes (neck, underarm, or groin)
• Unexplained fever that doesn't go away
• Unintended weight loss
• Itching all over that may be severe
• Fatigue
• Shortness of breath, cough, or discomfort in the chest
• Pain in the lymph nodes after drinking alcohol

Make an appointment with your doctor right away if you notice these symptoms.

Other Causes

Multiple other things can trigger night sweats, including:

• Medications: Antidepressants, over-the-counter analgesics (painkillers), beta-blockers, cholinergic agents, diabetes drugs such as insulin, hormone replacement therapy, triptans, Viagra (sildenafil)
• Dietary supplements: Calcium, niacin
• Hyperthyroidism: Additional symptoms include increased appetite, tremor, restlessness, goiter (a visibly enlarged thyroid gland), anxiety, and frequent bowel movements
• Neurologic disorders: Autonomic dysreflexia, syringomyelia

How to Stop Sweating While Sleeping

The solution to sweating while you sleep depends on what's causing the problem. If it's a medical condition, getting a proper diagnosis and treatment should alleviate the symptom. If it's the side effect of a medication, you and your doctor may need to revisit the risks versus rewards of the drug.

For other causes of night sweats, you can try:

• Keeping your bedroom cooler
• Moisture-wicking sleepwear and bedding
• Lighter or no pajamas
• Avoiding alcohol or hot beverages before bed
• Drinking cold water
• Not exercising right before bed

When to See a Doctor

Isolated incidents of nighttime sweating aren't anything to worry about. However, you should talk to your doctor if your night sweats are:

• Not explained by a previous diagnosis
• Not a medication side effect
• Extreme
• Frequent and persistent
• Interfering with sleep
• Affecting your daily life
• Accompanied by other symptoms

To get to the bottom of your sweating during sleep, your doctor may order a sleep study or other testing.