Night sweats: why they happen and when to get checked

What counts as a night sweat

Most people sweat a little at night if the room is warm. A true night sweat is different: you wake up with damp or soaked sheets or pajamas even though the room is comfortable. Some people have to change clothes or flip the pillow.

It helps to describe your episodes precisely. Do you wake hot and flushed for a few minutes, then feel chilled? That pattern points toward a hot flash happening at night. Do you wake drenched with no flush, or sweat through the day as well? That points the evaluation in other directions.

Hormonal causes

In women, night sweats are part of the group of vasomotor symptoms that also includes hot flashes. They usually start in perimenopause, when estrogen levels swing up and down, and can continue for years after the final period. Surgical removal of the ovaries and some breast cancer treatments can bring them on suddenly.

In men, a sharp drop in testosterone can cause hot flushes and sweating. The best-known example is hormone therapy for prostate cancer, which deliberately lowers testosterone. A gradual, age-related decline rarely causes drenching sweats on its own, so unexplained sweats in a man deserve a broader look.

Non-hormonal causes worth ruling out

Because so many conditions can trigger sweating, a clinician will usually ask about all of these before settling on a hormonal explanation:

• Medications: some antidepressants, opioids, steroids, thyroid hormone, fever reducers, and hormone-blocking cancer drugs such as tamoxifen or aromatase inhibitors
• Alcohol, and withdrawal from alcohol, sedatives or opioid pain medicines
• An overactive thyroid, which often brings heat intolerance, a fast heartbeat and weight loss
• Low blood sugar overnight, especially in people taking insulin or other glucose-lowering drugs
• Infections, including some that smolder for weeks
• Obstructive sleep apnea, often with loud snoring and daytime sleepiness
• Anxiety and panic, which can wake you sweating with a racing heart
• Less commonly, cancers such as lymphoma

When to see a doctor urgently

Most night sweats are not dangerous, but some combinations of symptoms should not wait for a routine appointment. Arrange an in-person evaluation promptly if you notice any of the following:

• Fever that keeps coming back without an obvious infection
• Unintended weight loss
• New, painless swollen lymph nodes in the neck, armpit or groin
• A persistent cough, especially with blood
• Sweating that continues around the clock with a pounding heart or tremor
• Sweating with chest pain, shortness of breath or confusion: call 911

What testing can help

There is no single blood test for night sweats. Testing is guided by your history and is mainly used to rule other causes in or out. A clinician may consider a complete blood count, thyroid function (TSH, sometimes with free T4), blood glucose or A1c, and a metabolic panel. In men, a morning total testosterone, repeated if low, can be useful.

Hormone levels are less helpful for women in perimenopause because estrogen and FSH fluctuate from week to week; the diagnosis rests mainly on age, cycle changes and symptoms. If sleep apnea is suspected, a sleep study is what confirms it. A two-week diary of episodes, alcohol, medications and bedroom temperature often reveals more than any lab.

Treatment options in general terms

Treatment depends on the cause. Medication-related sweats may improve if a prescriber adjusts the dose, timing or drug. Thyroid disease, infection and sleep apnea are treated directly.

For menopause-related night sweats, simple steps such as a cool bedroom, layered bedding, breathable sleepwear and limiting evening alcohol help some women. Cognitive behavioral therapy and hypnosis have evidence for reducing how bothersome symptoms feel. Prescription options include menopausal hormone therapy, which is the most effective treatment for vasomotor symptoms, and FDA-approved non-hormonal medicines. Hormone therapy has risks, including blood clots, stroke and breast cancer, that depend on your age, timing and health history, and women with a uterus need a progestogen to protect the uterine lining.

How HealifyMD can help

If your sweats fit the menopause pattern, a HealifyMD clinician can review your history online, order labs to rule out thyroid and blood count problems, and talk through whether hormone therapy or a non-hormonal approach makes sense for you. Men with symptoms of low testosterone can be evaluated with properly timed testing.

HealifyMD is telehealth only. If your symptoms include any of the red flags above, or you need an exam, imaging or a sleep study, we will point you to in-person care first.