Certain medications give rise to night sweats and may leave you tossing and turning throughout your sleep. Antidepressants are the most common drug associated with what causes night sweats, with anywhere from 8 to 22 percent of patients who use them reporting overheating at night. Night sweats are often seen with other psychiatric drugs, but even over-the-counter anti-fever medications like acetaminophen and ibuprofen can cause your body to heat up in bed, too.
Low blood sugar
For people with type 1 diabetes, waking up throughout the night in fits of heat may be your body’s way of alerting you to low blood sugar, also known as hypoglycemia. Night sweats, along with other symptoms of low blood sugar, like headaches and nightmares, may occur if you don’t inject the correct amount of insulin right before you hit the sheets, according to the online resource Diabetes Self Management. Fortunately, these bouts of sweat are treatable, as taking preventative measures like eating a late night snack can help even out your insulin levels.
A long-term infection
If your night sweats begin to occur more regularly and more severely, it may be the sign of a more serious issue. Instead of what causes night sweats, the question becomes what health issues cause night sweating symptoms. For example, night sweats are one of the primary symptoms of tuberculosis, a potentially dangerous infectious disease that affects the lungs. They also can be a sign of bacterial infections like endocarditis (heart valve inflammation) and osteomyelitis (bone inflammation), as well as an early marker of HIV.
Chronic night sweats are often one of the first visible signs of a lymphoma diagnosis. In this case, the hot flashes are incredibly intense—so much so that they may require you to actually change clothes to dry off. However, it’s important to note that any type of cancer would be accompanied by other symptoms as well, so be sure to check with a doctor before contemplating a scary diagnosis.
What causes night sweats might be because of hormonal changes. Most women going through menopause are no stranger to hot flashes, and these intense spells of heat often occur at night. Night sweats during menopause are the result of changing estrogen levels and their effects the hypothalamus, the part of your brain that regulates temperature and deals with hormones. Menopause causes your estrogen levels to waver, which can confuse the hypothalamus. “Like a faulty thermostat, the hypothalamus may respond to the changes in estrogen as if it senses an increase in your body’s temperature,” according to everydayhealth.com. Then, while trying to cool you down, the hypothalamus tells your blood vessels to dilate and your sweat glands to release perspiration, leaving you hot and sweaty.
Persistent night sweats may be caused by various problems in the endocrine system—the part of your body that produces hormones, according to the American Osteopathic Association. If these glands produce too much or not enough of a hormone, such as serotonin or estrogen, you may find yourself heating up while you doze off. Additionally, the AOA notes that night sweats are also a common side effect of hormone-regulating medications.
Anxiety disorders have physical symptoms in addition to emotional ones, too. According to the Mayo Clinic, people with anxiety disorders such as generalized anxiety disorder, panic disorder, and social anxiety disorder can all experience excessive night sweating. Plus, if you worry about excessive sweating, this adds to the anxiety creating a vicious cycle of more sweat.
Night sweats are linked to both under and overactive thyroids, according to the American Association of Endocrine Surgeons. Hyperthyroidism means the thyroid is overactive and produces or releases excess thyroid hormone. This extra activity contributes to other symptoms like irritability, insomnia, and increased sensitivity to heat, as well as sweating.
Obstructive sleep apnea syndrome
Obstructive sleep apnea syndrome, or OSAS, is a sleep disorder that causes problems with breathing while you sleep, leading to repeated sleep interruptions. Night sweats are one symptom of the syndrome along with loud snoring and noisy breathing. One case study found that using a CPAP machine was a successful treatment for excess sweating of an OSAS patient.
Neurological conditions and disorders are less-common causes of night sweats. Some possibilities, however, include stroke, autonomic dysreflexia, and autonomic neuropathy. Autonomic neuropathy is actually a group of symptoms—sweating, dizziness, digestion issues—among others that could be caused by a whole host of other health issues like diabetes, nerve injuries, and Parkinson disease.
Or, you might just sweat a lot
Not every case of night sweats is linked to a serious issue or health concern. In many situations, what causes night sweats or overheating in bed is simply linked to a tendency to sweat more than usual without any identifiable reason. This is known as idiopathic hyperhidrosis. This condition may affect just one area—like your arms, underarms, feet, or face—or it may lead you to sweat all over. Because the cause for idiopathic hyperhidrosis is unclear, the night sweats it causes can be treated with preventative measures like holding off on caffeine and spicy foods before bed, and sleeping in something cool and comfortable.