Severe night sweats are pronounced, and people who wake up may discover soggy nightwear and sheets or blankets. They are often associated with the hot flashes women experience when they are perimenopausal or menopausal, but this is just one of a number of common causes of severe night sweats. A variety of medical conditions, infections, and medications can also cause this symptom.
People can experience the rare episode of night sweats due to something else, such as eating very spicy foods. In general, severe night sweats are best defined as something that occurs fairly regularly or over a period of time that a specific condition could also be defined. It's worth noting that the potential severity of some common causes of night sweats means that this symptom should be mentioned to doctors, unless the cause is clearly benign and transient, such as several months of especially hot and humid nights.
Some medical conditions are common causes of severe night sweats. As mentioned, perimenopause and menopause are known causative factors, and women can also experience daytime hot flashes. Pregnancy can occasionally cause night sweats as well.
Another medical condition called idiopathic hyperhidrosis leads to excessive sweating both day and night. Hypoglycemia, or persistently low blood sugar, can cause this condition, as can hyperthyroidism, or too much thyroid hormone. Some cancers, particularly lymphoma, can also cause severe night sweats. A tumor in one of the adrenal glands, called a pheochromocytoma, is rare, but it can also be the cause of these profuse night sweats.
Certain infectious viruses like the flu virus, especially when accompanied by a fever, can cause night sweats. The most resistant incurable viruses, such as AIDs, are also known to cause this symptom. Bacterial infections that are common causes of severe night sweats include tuberculosis or heart and bone infections, but more common bacterial infections of the lungs or throat, such as pneumonia or strep throat, can cause night sweats, especially if you have a fever.
A large number of medications can be common causes of severe night sweats, and many of these medications are used frequently. For example, many types of antidepressants create this condition in about 20% of people who use them, and the popular erectile dysfunction drug Viagra® can have this side effect. Commonly used fever reducers like acetaminophen and aspirin have been linked to a higher incidence of night sweats. Other medications that can create this problem include thyroxidine (Synthroid®), insulin, which can lead to low blood sugar if not carefully monitored, prednisone, prednisolone, tamoxifen, niacin, and nitroglycerin. Patients can read about the possible side effects of the medications they take to see if other medications list this as a symptom; Many medications that list flushing as a side effect can also cause severe night sweats.