Night sweats? 10 reasons for sweating while sleeping

The experience of waking up in the middle of the night drenched in sweat – enough to soak your clothing, bed sheets and pillow – is not only uncomfortable but disturbing. Wearing too many bed clothes, sleeping under too many blankets, or sleeping in an overheated room is one thing, but to waking up night after night covered in extreme perspiration, could be a warning sign of an underlying medical condition or illness.

Night sweats, scientifically known sleep hyperhidrosis, is defined as the occurrence of excessive sweating during sleep. The excessive sweating can be significant enough to drench clothing and sheets which is not related to an overheated environment. A person may or may not have excessive sweating during waking hours.

There can be many different causes of night sweats. Anyone who is experiencing night sweats that have suddenly started should see their healthcare professional. Night sweats can be indicative of several things some of which could be a serious health condition. By seeing a doctor, they will do a detailed medical history and order tests to determine the cause triggering night sweats.

Here are 10 conditions possibly behind why night sweats are occurring:

1. Menopause – Women going through menopause may have hot flashes that can occur during the night resulting in sweating. Hot flashes are common for many women but they also can and do occur during the daytime. Generally, they do not result in soaking clothing or bedsheets.

2. Idiopathic hyperhidrosis – Also known as primary hyperhidrosis, this is a chronic condition where the body simply produces too much sweat. The cause is generally unknown (idiopathic) but it can have strong psychological impacts and can affect daily functioning. Many people avoid seeking treatment due to embarrassment therefore often causing social anxiety at work, school and social functions. Excessive sweating associated with idiopathic hyperhidrosis typically involves sweating of the armpits, palms of the hand or soles of the feet, and occasionally facial sweating. This condition generally occurs by or before adolescence and is often inherited.

3. Infections – Certain infections can result in excessive sweating. Tuberculosis is commonly associated with night sweats but even bacterial infections such as endocarditis (inflammation of the heart), osteomyelitis (inflammation in the bones), and abscesses can cause night sweats. HIV infection can also result in night sweats.

4. Cancer – An early symptom of some cancers can be night sweats. Night sweats are common in the early stages of lymphoma but other symptoms of unexplained weight loss and fevers are also common symptoms of this disease.

5. Medications – It is not unusual for certain medications to result in excessive sweating during the night. One common one is the use of antidepressants and other psychiatric drugs. Anywhere from 8% to 22% of people using antidepressants have night sweats. Medications used to reduce fever such as aspirin and acetaminophen, can sometimes lead to night sweats.

6. Low blood sugar or hypoglycemia – Individuals with either type 1 or type 2 diabetes may experience low blood sugar at night leading to sweating while sleeping. Hypoglycemia generally refers to blood sugar dropping below 70 mg/dl. When blood sugar drops below this number, the nervous system reacts in a number of ways. One reaction is sweating, either as traditional night sweats or cold sweats at night. Sweating can also be accompanied by shakiness, hunger, weakness, or fatigue along with a sense of nervousness or anxiety. This is the body’s way of expressing the need to restore blood sugar to a normal level.

7. Hormonal disorders – Several hormonal disorders are associated with excessive sweating at night which include hyperthyroidism, and carcinoid syndrome.

8. Adrenal gland disease (pheochromocytoma) – A tumor that causes excessive autonomic nervous system function, adrenal gland disease can cause sweats and flushing, and it usually also causes a rapid heartbeat, high blood pressure, and anxiety.

9. Pregnancy – While not a medical illness, pregnancy can cause unpleasant symptoms, including discomfort when trying to sleep, a sense of feeling too hot, and sweating during the day or night.

10. Drug or alcohol withdrawal – Alcohol and drugs may cause sweating, and withdrawal can cause severe temperature dysregulation, manifesting as fevers or intermittent sweating.