The Prevalence of Night Sweats
Night sweats are one of the most commonly reported symptoms. In one study, 41% of patients of a primary care clinic reporting having some episodes of night sweats.
Of these patients, 23% had pure night sweats, meaning they only experienced excessive sweating at night, and 18% experienced excessive sweating during both night and day.
Top 3 Causes of Night Sweats
Source: Are night sweats a sign of esophageal reflux?
Fortunately, night sweats are a completely harmless occurence for the vast majority of people.
While there is not a lot of data on the subject, one study did try to find the most common causes of night sweats among mostly healthy patients. Similar to the previous study, they found that 81/200 patients reported getting night sweats.
After checking their medical records, researchers tried to determine the causes of their night sweats.
They found that the most common cause was gastric reflux. This is where stomach acid flows back into your esophagus, the tube connecting your mouth to your stomach. This is usually the cause of heart burn. It can also cause night sweats.
After a big dinner with spicy and greasy food, a person may get sleepy. As heart burn sets in overnight, they will start to sweat and they may wake up with damp clothing.
The second most common cause was menopause. Along with hot flashes, women going through menopause may also experience excess sweating.
Third is external causes. If your room is too hot or your blankets are too thick, you may wake up sweaty. It sounds obvious, but it happens.
A small number of patients had either multiple or unknown causes.
Potentially Dangerous Causes of Night Sweats
While the vast majority of people with night sweats are completely healthy, there are a few potentially dangerous conditions that can also lead to night sweats. If you get recurring night sweats, be sure to tell your doctor.
Lymphoma is a cancer that arises from your immune cells. Patients with lymphoma often have a trio of symptoms called B Symptoms. These are Fever, Night Sweats, and unexplained Weight Loss.
Night sweats in the case of B Symptoms are not like your run of the mill damp t-shirt type of night sweats. These are typically drenching sweats where you soak through your sheets.
Tuberculosis can also cause Night sweats. Tuberculosis is a bacterial infection of the lungs. While this is relatively rare in the United States, people can still get it when traveling abroad or from someone who has travelled recently.
Along with tuberculosis, other infections have been known to cause night sweats as well. These include HIV, dental absceccess, and other bacterial infections.
Medications That Cause Night Sweats
Medications can also cause night sweats as a side effect. If you are on one of these medications and you get night sweats, there is a good chance that your medication is causing it.
Source: Drug-induced hyperhidrosis and hypohidrosis: incidence, prevention and management
SSRIs, including Zoloft, are some of the most prescribed medications in the United States. They also can cause excessive sweating. According to one paper, 10% of patients reported sweating as a side effect.
Opioids can also cause excessive sweating. While the evidence is thin, one study in the paper above did show nearly half of patients on methadone experienced excessive sweating.
Viagra, and its generic versions, have been known to cause sweating in a minority of patients. These drugs are vasodilators, meaning they function by widening your blood vessels, which potentially leads to excess sweating.