Dear Doctor: How common are night sweats in men, and what causes them? I tease my husband that he’s having sympathy hot flashes, but he’s not amused. The sweats usually happen between 3 a.m. and 6 a.m. Neither his primary care physician nor cardiologist have an answer.
Dear Reader: It’s true that because night sweats are associated with hormonal shifts during menopause, they are often seen as an issue that affects women. However, as your husband knows firsthand, they can happen to people of any sex. Unlike occasional bouts of nighttime perspiration, which can arise when the bed or the bedroom are too warm, or when you’re ill and have a fever, night sweats are defined as repeated episodes of extreme sweating. Even when the room they are sleeping in is cool, someone with night sweats will awaken to find themselves, their pajamas and even their bedding drenched in perspiration.
Sweating is a cooling mechanisms that helps to maintain the narrow temperature range the body’s physical and chemical processes require for optimal function. When your body signals that your core temperature is rising, a small area of the brain known as the hypothalamus sends out an alert. It activates certain sweat glands, which secrete a clear, odorless fluid, composed mostly of water, that evaporates and cools the body. How much you sweat typically depends on temperature and humidity, and on physical exertion, which generates internal heat. Stress, fear and other emotions can also have an impact on sweating. So can alcohol, spicy foods and certain medications and medical treatments.
When heavy sweating becomes chronic, it’s called hyperhidrosis. When it occurs at night, it’s known as nocturnal hyperhidrosis. And because our bodies actually cool down a degree or two during sleep, nocturnal hyperhidrosis can be an indicator of an underlying problem or condition.
One possible cause of night sweats in men is low testosterone, which can be identified via a simple blood test. It’s a hormonal condition that becomes more common as men age. Low testosterone has been linked to being overweight and to Type 2 diabetes. Because it can also be a sign of infection; liver, kidney or pituitary gland disease; or an autoimmune disease, a diagnosis of low testosterone can lead to additional testing.
Other medical conditions that can cause night sweats include hypoglycemia, infection, HIV and certain cancers, such as lymphoma or leukemia. Medications for depression, diabetes and hormone treatments can also play a role. And, as we mentioned earlier, so can alcohol and tobacco use. Researchers in Spain tied night sweats in some patients to gastroesophageal reflux disease, often referred to as acid reflux. This is when the band of muscle at the base of the esophagus is no longer able to prevent the contents of the stomach from flowing backward.
As you can see, night sweats have a number of different triggers. Unfortunately, this makes it difficult to pinpoint the source. If your husband’s episodes continue and his doctors don’t have any thoughts on the issue, we think it would be worthwhile to seek another opinion.
(Send your questions to firstname.lastname@example.org, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)