Waking up drenched in sweat can be alarming. Maybe you’ve had to change your pajamas, replace your bedsheets, or turn on a fan in the middle of the night. While occasional sweating during sleep is common—especially in a warm room—true night sweats are different.

Night sweats can sometimes be harmless, but they can also be a sign of an underlying medical condition that deserves attention.

Understanding the possible causes can help you determine when lifestyle changes may be enough and when it’s time to talk to a healthcare professional.

What Are Night Sweats?

Night sweats refer to episodes of excessive sweating during sleep that are significant enough to soak clothing or bedding.

They are different from:

• Feeling slightly warm at night
• Sweating because the room is hot
• Using too many blankets

True night sweats often occur even when the sleeping environment is cool and comfortable.

Common Causes of Night Sweats

Many different factors can trigger night sweats.

Some are relatively benign, while others require medical evaluation.

Menopause and Hormonal Changes

One of the most common causes in women is:

Menopause

and

Perimenopause

Fluctuating hormone levels can trigger:

• Hot flashes
• Sudden sweating
• Nighttime awakenings

For many women, night sweats are among the earliest signs of hormonal transition.

Stress and Anxiety

Emotional stress can activate the body’s fight-or-flight response.

This may lead to:

• Increased heart rate
• Elevated stress hormones
• Excessive sweating

Night sweats related to anxiety are often accompanied by:

• Restlessness
• Racing thoughts
• Poor sleep quality

Infections

Various infections can cause night sweats as the immune system responds.

Examples include:

• Influenza
• Viral illnesses
• Certain bacterial infections

When infection is responsible, night sweats are often accompanied by:

• Fever
• Chills
• Fatigue
• Other signs of illness

Medications

Several medications are known to cause night sweats.

Examples include:

• Certain antidepressants
• Some diabetes medications
• Hormone therapies
• Fever-reducing medications

If symptoms began after starting a new medication, discuss it with your healthcare provider.

Never stop prescribed medication without medical guidance.

Low Blood Sugar During the Night

People with diabetes may experience nighttime sweating when blood sugar drops too low.

This may be associated with:

• Restless sleep
• Nightmares
• Morning headaches
• Waking suddenly

Individuals using insulin or certain diabetes medications should discuss recurrent episodes with their healthcare team.

Sleep Disorders

Certain sleep disorders may contribute to night sweating.

Examples include:

Obstructive Sleep Apnea

People with sleep apnea may also experience:

• Loud snoring
• Gasping during sleep
• Morning headaches
• Daytime fatigue

Causes More Common in Men

While many causes affect both sexes, some are particularly relevant for men.

Low Testosterone

In some men, lower levels of:

Testosterone

may contribute to:

• Hot flashes
• Night sweats
• Reduced energy
• Changes in mood

Evaluation is appropriate when symptoms occur alongside other signs of hormone imbalance.

Thyroid Disorders

An overactive thyroid can increase body heat production.

People with:

Hyperthyroidism

may experience:

• Excessive sweating
• Weight loss
• Rapid heartbeat
• Anxiety
• Heat intolerance

Night sweats may be one of several symptoms.

Cancer and Night Sweats

Many people worry about cancer when they experience night sweats.

While certain cancers can cause night sweats, they are a much less common cause than menopause, infections, medications, or sleep disorders.

Examples include some forms of:

Lymphoma

Night sweats related to serious illness are often accompanied by additional symptoms such as:

• Unexplained weight loss
• Persistent fever
• Enlarged lymph nodes
• Significant fatigue

Autoimmune and Inflammatory Conditions

Some inflammatory diseases may contribute to night sweating.

Examples include:

• Rheumatoid arthritis
• Certain autoimmune disorders
• Chronic inflammatory conditions

Symptoms usually extend beyond sweating alone.

Lifestyle Factors That Can Contribute

Several everyday habits may increase nighttime sweating.

Examples include:

• Alcohol consumption
• Spicy foods close to bedtime
• Excess caffeine
• Smoking
• Heavy bedding
• Warm sleeping environments

Addressing these factors may improve symptoms.

When Should You See a Doctor?

Occasional night sweats are usually not an emergency.

However, medical evaluation is recommended if night sweats:

• Occur frequently
• Persist for weeks
• Disrupt sleep significantly
• Are worsening over time

You should also seek medical attention if night sweats occur with:

• Unexplained weight loss
• Persistent fever
• Enlarged lymph nodes
• Severe fatigue
• Chronic cough
• New neurological symptoms

These combinations may indicate an underlying condition requiring evaluation.

What Tests Might Be Ordered?

Depending on your symptoms, a healthcare provider may recommend:

• Blood tests
• Thyroid testing
• Infection screening
• Hormone evaluation
• Sleep studies
• Imaging studies in select cases

The goal is to identify or rule out underlying causes.

How to Reduce Night Sweats

While treatment depends on the cause, general strategies may include:

Keep the Bedroom Cool

Lower room temperatures often improve comfort.

Choose Breathable Bedding

Lightweight fabrics may help reduce overheating.

Limit Alcohol Before Bed

Alcohol can worsen nighttime sweating in some individuals.

Manage Stress

Relaxation techniques may help if anxiety contributes to symptoms.

Maintain a Healthy Weight

Excess body weight may increase sweating and worsen sleep disorders such as sleep apnea.

Common Myths About Night Sweats

Myth: Night Sweats Always Mean Cancer

Reality:
Most night sweats are caused by much more common and less serious conditions.

Myth: Only Women Get Night Sweats

Reality:
Men can also experience night sweats due to infections, medications, hormonal changes, sleep disorders, and other medical conditions.

Myth: Sweating at Night Is Always Normal Aging

Reality:
Persistent or severe night sweats should not automatically be dismissed as part of aging.

Bottom Line

Night sweats can result from a wide range of causes, including menopause, stress, infections, medications, low blood sugar, thyroid disorders, sleep apnea, and hormonal changes. In many cases, they are manageable and not a sign of serious illness.

However, persistent, severe, or unexplained night sweats—especially when accompanied by symptoms such as fever, weight loss, enlarged lymph nodes, or significant fatigue—deserve medical evaluation. Identifying the underlying cause is the key to finding effective treatment and improving sleep quality.