Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.
Sweating at night can be a regular occurrence. Maybe the heater is too high, you’re wearing flannel pajamas, or perhaps you’ve eaten spicy or fatty food right before bedtime.
The occasional light night sweat is not usually a cause of concern; however, recurring excessive sweat that drenches the clothes and bedsheets can indicate a serious illness and should not be ignored.
People sometimes complain that they wake up with their clothes and sheets completely soaked with sweat.
Infections, neurological conditions, certain types of cancers, hormonal changes, and other medical disorders can cause this type of night sweat, among other symptoms.
If you experience night sweats with other worrying symptoms, like chills or a fever, you should schedule an appointment with your doctor.
While you’re sleeping, your blood vessels initially expand, increasing the blood flow through your whole body. This vasodilation is temporary, and the vessels soon contract again to restore physiologic blood circulation.
Physiologically, however, this can send a sudden wave of heat throughout your body. As a result, you’ll sweat, your skin becomes flushed, and your heart rate increases.
There are a lot of factors that can make you sweat during the nighttime. It’s not uncommon to sweat while sleeping if:
- Your room is stuffy or hot
- You wear heavy layers of clothes to bed
- You cover up with a lot of blankets
- You eat food that produces a lot of acid before bed (citrus, spicy, or high-fat food)
In these cases, you probably shouldn’t worry about your night sweats. On the other hand, night sweating can sometimes be a symptom of an underlying condition that requires medical attention, such as:
- Brucellosis (bacterial infection)
- Endocarditis (an infection of the inner lining of the heart)
- HIV/ AIDS
- Osteomyelitis (an infection that spreads to the bones)
- A pyogenic abscess (pus-filled abscess)
- Valley fever (fungal infection)
In addition to night sweats, infections usually cause other troubling symptoms, including:
- Fever and chills
- Muscle and joint pain
- Weakness and fatigue
- Weight loss
- Lack of appetite
2) Hormonal Changes
Excessive nighttime sweating can be triggered by hormonal issues:
- Hormonal therapy (for breast or prostate cancer, menopausal symptoms, estrogen deficiency)
- Menopause or perimenopause (lower estrogen leads to hot flashes and night sweats)
- Hyperthyroidism (overactive thyroid produces too much thyroxine hormone)
Other than sweating at night, irregular hormonal levels can cause:
- Unintentional weight changes
- Changes in energy levels
- Sexual dysfunction
- Menstrual changes
Unexplained drenching night sweats can be a symptom of certain cancers:
- Non-Hodgkin’s lymphoma
- Hodgkin’s lymphoma
- Carcinoid tumors (neuroendocrine tumors)
- Myelofibrosis (an uncommon bone marrow cancer)
Undiagnosed cancer can cause other symptoms:
- Chronic fatigue
- Fever and chills
- Unexplained weight loss
- Pain in the chest, stomach, or bones
- Swollen lymph nodes
You might experience nighttime sweating after starting a new medication:
- Methadone (that treats opioid use disorder)
- Hypoglycemic agents (diabetes medications)
- Cancer treatments (aromatase inhibitors, tamoxifen, steroids)
- Blood pressure drugs
- Pain meds and antiinflammatory drugs (Acetaminophen, Aspirin)
5) Psychiatric Disorders
Some mental and psychiatric disorders can cause night sweats:
- Alcohol use disorders
- Drug addiction (substance use disorder)
- Anxiety or panic disorders
These disorders share other common symptoms:
- Mood changes
- Feeling irritable
- Feeling anxious and on edge
- Having trouble sleeping and unpleasant dreams
Like anxiety and depression, mental disorders are also associated with obstructive sleep apnea (OSA). OSA needs to be ruled out if you’re having a bad sleep quality, night sweats, and mood instability.
6) Neurologic Conditions
Less frequently, night sweats can occur as a result of neurological problems:
- Autonomic neuropathy (damage to autonomic nerves)
- Dysreflexia (overreaction of the involuntary nervous system in response to stimulation)
- Post-traumatic Syringomyelia (cyst in the spinal cord)
Neurologic issues can involve a variety of other symptoms:
- Loss of appetite
- Gastrointestinal or urinary problems
- Loss of consciousness
- Feeling dizzy or lightheaded
- Weakness in the muscles
- Tingling sensation in the hands, feet, arms, and legs
7) Other Causes
You might be sweating too much during sleep because of other conditions:
- A cold or the flu (can spike a fever)
- gastroesophageal reflux disease (GERD)
- Autoimmune disorders
- Idiopathic hyperhidrosis (body chronically produces too much sweat without a known cause)
Consult with a sleep doctor if your night sweats are frequent, disturbing your sleep, or are accompanied by other worrisome symptoms.
When to See a Sleep Specialist
If you rarely sweat during your sleep and it does not disturb your sleeping pattern, you probably don’t need to worry. However, you can mention it during your next doctor visit or checkup.
But if you’re sweating too much while you sleep and are also experiencing trouble sleeping and other worrying symptoms, you should consult with a sleep doctor.
Some of the concerning symptoms that are associated with night sweats and require medical attention are:
- Unexplained weight changes
- Body aches
- Fever and chills
- A persistent cough that may be bloody
- Bowel problems (stomach ache, diarrhea)
Your sleep doctor will gather your health information, get your family medical history, and discuss other symptoms you’re having.
If cancer, infection, or other health conditions are suspected, you might get a physical exam, laboratory tests, or imaging tests.
How to Alleviate Night Sweats
In case your excessive night sweats are not accompanied by other concerning health symptoms, you can try the following tips on how to stop night sweats:
- Wear light and loose-fitting clothes to bed
- Keep the room aerated (turn on a fan, open a window)
- Use light bedding and covers that can be removed easily during the night
- Drink cool water throughout the night
- Place a cool pack under the pillow and turn the pillow over to keep your head cool
- Avoid alcohol, spicy food, cigarettes, caffeine, and exercises before bed because they can trigger your night sweats
- Perform daily exercises to alleviate your anxiety and restlessness
- Seek therapy for mental health issues
Many things can make you sweat while you’re sleeping. First, check your sleeping environment, then your bedtime sleeping habits (what you eat, drink, smoke, do before bed).
If all those things are regulated, and you still get night sweats, consult with a sleep doctor to get a diagnosis and help you get back to sleeping comfortably.
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