Menopause – The hot flashes that accompany the menopausal transition can occur at night and cause sweating. This is a very common cause of night sweats in perimenopausal women.
Idiopathic hyperhidrosis – Idiopathic hyperhidrosis is a condition in which the body chronically produces too much sweat without any identifiable medical cause.
Infections – Classically, tuberculosis is the infection most commonly associated with night sweats. However, bacterial infections, such as endocarditis (inflammation of the heart valves), osteomyelitis (inflammation within the bones), and abscesses all may result in night sweats. Night sweats are also a symptom of AIDS virus (HIV) infection.
Cancers – Night sweats are an early symptom of some cancers. The most common type of cancer associated with night sweats is lymphoma. However, people who have an undiagnosed cancer frequently have other symptoms as well, such as unexplained weight loss and fevers.
Medications – Taking certain medications can lead to night sweats. In cases without other physical symptoms or signs of tumor or infection, medications are often determined to be the cause of night sweats. Antidepressant medications are a common type of medication that can lead to night sweats. All types of antidepressants can cause night sweats as a side effect, with a range in incidence from 8 to 22% of persons taking antidepressant drugs. Other psychiatric drugs have also been associated with night sweats. Medicines taken to lower fever such as aspirin and acetaminophen can sometimes lead to sweating. Other types of drugs can cause flushing, which, as mentioned above, may be confused with night sweats. Some of the many drugs that can cause flushing include:
niacin (taken in the higher doses used for lipid disorders),
tamoxifen,
hydralazine,
nitroglycerine, and
sildenafil (Viagra).
Many other drugs not mentioned above, including cortisone medications such as prednisone and prednisolone, may also be associated with flushing or night sweats.

Hypoglycemia – Sometimes low blood glucose can cause sweating. People who are taking insulin or oral anti-diabetic medications may experience hypoglycemia at night that is accompanied by sweating.
Hormone disorders – Sweating or flushing can be seen with several hormone disorders, including pheochromocytoma, carcinoid syndrome, and hyperthyroidism.
Neurologic conditions – Uncommonly, neurologic conditions including autonomic dysreflexia, post-traumatic syringomyelia, stroke, and autonomic neuropathy may cause increased sweating and possibly lead to night sweats