Why You’re Having Night Sweats and When to Worry

Waking up at night drenched in sweat is a jarring experience. Though uncomfortable, night sweats are typically a harmless side effect of several manageable conditions. Collette Kono, PA-C, UnityPoint Health, breaks down different causes — from hormonal shifts and lifestyle factors to red flags that signal serious illnesses.

Understanding the Sensation of Sweating at Night

Night sweats aren't always a full-body event. Often, sweating is contained to the neck and chest at night as well as dampness along the torso. Sweating solely on one area of the body, like the legs, is less common.

While some people describe the sensation as a sudden "hot flash," others wake up shivering from what feels like "cold sweats.” Kono says these are two stages of the same process: the body overheating and then rapidly cooling down.

"When you experience a rush of heat, your body breaks out in a sweat to cool itself off. If you then wake up in a cold room, that moisture starts to evaporate," Kono says. "As your temperature drops back to normal, you're left feeling cold and clammy."

Why are Hot Flashes Worse at Night?

Naturally, your body tries to cool down to help you fall asleep. However, when estrogen levels dip, your brain mistakenly thinks you’re overheating. This triggers a sudden hot flash right as your body is attempting to reach its lowest temperature.

In a quiet, dark room, you don't have daytime activities to distract you, so the heat feels more intense.

Night Sweats in Women: Common Causes

For women, the most common cause of night sweats is tied to shifting hormone levels, which can disrupt your body’s temperature regulation depending on your stage of life. These fluctuations occur in a few predictable ways:

• Night sweats before your period: A drop in estrogen right before your menstrual cycle can cause sweating. Kono assures, "It’s not a sign of early menopause. As long as there’s a pattern to it, that’s likely your body’s unique rhythm."
• Night sweats during pregnancy and postpartum: Hormone fluctuations during and after pregnancy are notorious for interrupting sleep. Postpartum night sweats are particularly common as your body recovers from giving birth and if you’re breastfeeding. Because breastfeeding keeps the body in a state of estrogen deficiency, temperature dysregulation can persist if you’re nursing.
  
  “If night sweats continue for several months after you’ve stopped breastfeeding, and your period has returned, talk to your doctor. In these cases, your doctor may check your complete blood count or thyroid levels to rule out postpartum thyroid issues,” Kono says.
• Night sweats during menopause: This is the most common culprit of night sweats. As estrogen levels drop during menopause, your body's thermostat becomes more sensitive.
  
  "You're not technically postmenopausal until you've gone 12 months without a period," Kono says, “but perimenopause symptoms can start much earlier.” While a hallmark symptom, Kono says women don’t have to tolerate night sweats as part of the menopause package. "It’s definitely important to address. There are all kinds of good treatment options,” she says.

Night Sweats in Men

Night sweats happen in men, too, although the hormonal connection isn’t as common as it is in women. There’s a possible link between low testosterone and night sweats in some males, accompanied by additional symptoms such as fatigue, low libido, trouble concentrating, muscle loss and anxiety or depression.

How to Treat Night Sweats in Males

Treatment depends on the reason for the night sweats, but a simple blood test can confirm testosterone levels in men. While low testosterone is a natural part of aging, it can also be a byproduct of other underlying issues — such as infections, autoimmune conditions, or concerns with the liver, kidneys or pituitary gland.

Other Reasons for Night Sweats

If hormones aren't the answer to why you’re experiencing night sweats, several other conditions might be at play:

• Alcohol withdrawal and night sweats are common. After your nervous system loses the sedative effects of alcohol, your brain’s regulatory systems overcompensate, causing a spike in heart rate and major fluctuations in body temperature.
• Anxiety and night sweats are linked to medication. Antidepressants, known as selective serotonin reuptake inhibitors (SSRIs), are common triggers. However, if medication is the cause, it’s more likely to consistently feel hot throughout the day versus just having night sweats.
  
  “If the night sweats only happen on occasion, most patients choose to stay on their anxiety and/or depression medication, because the benefits outweigh the annoyance,” Kono says.
• Chronic conditions, like diabetes, can cause night sweats if you have an infection, too. But it’s not the main presenting symptom. Kono says excessive thirst is more common.
• Hyperthyroidism, when the thyroid is overactive, causes night sweats along with diarrhea, anxiety and a racing heart. Hypothyroidism does not. Kono recommends getting a complete blood count (CBC) test if the symptom persists.
• Infections and night sweats go together. Whether it's a virus or bacterial infection, such as strep throat, pneumonia or COVID-19, night sweats when you’re sick happen when a fever is "breaking" during the night.
• Sleep apnea and night sweats coexist, too. When you stop breathing, your body panics and goes into "fight-or-flight" mode. This stress causes a burst of adrenaline that heats up your body.

When are Night Sweats a Red Flag?

Night sweats are worrisome when additional symptoms are present that aren’t typical for a person’s age or lifestyle. For example, night sweats in a young person are worth getting checked out.

Kono says, “If you have unexplained weight loss and night sweats, or if the sweating is accompanied by fevers, a persistent cough (especially if you’re coughing up blood), swollen lymph nodes in the neck or armpits, unexplained rashes or easy bruising, make an appointment with your doctor.”

Night Sweats and Cancer

Cancers and serious illnesses that include night sweats as a symptom include lymphoma, leukemia, carcinoid tumors, tuberculosis and HIV/AIDS.

How to Prevent Night Sweats

The best way to stop night sweats is to first identify the underlying cause — whether that’s adjusting a thyroid dosage, managing menopause with hormone therapy or clearing an infection.

To reduce night sweats at home, try the following:

• Invest in cooling sheets, moisture-wicking blankets or cooling mattress pads.
• Keep the room cool to help your body temperature regulate.
• Use a ceiling fan or a bedside fan to keep air moving.

Making your nighttime environment more comfortable can offer some much-needed relief. However, if your night sweats are persistent, drenching or paired with other "red flag" symptoms like unexplained weight loss or fever, talk to your doctor. They can help rule out any serious conditions and create a treatment plan that works for you.

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