Causes of Night Sweats

woman sweating in bed
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Night sweats are a nuisance. They can also be a sign of a medical condition, including a hormonal imbalance, cancer, or an infection. Symptoms that are very similar to night sweats, such as hot flashes or flushing, can also signal a medical problem. If you experience night sweats, it is important that you discuss this with your doctor. There is a wide range of causes and solutions that should be explored, some of which may require immediate treatment.

Defining Night Sweats

Feeling sweaty or overheated at night can be described in several ways, and you may be experiencing clear-cut symptoms of night sweats or a combination of several different experiences, including hot flashes and flushing.

  • Night sweating is defined as sweating so profusely that your bed clothes, and possibly even your linens, are damp and need to be changed.
  • Hot flashes are sudden, strong, warm sensations that may begin in the chest or arms and move upward to your face. They can occur at any time of the day, not just at night.
  • Flushing is the sudden rise in body temperature that can cause a rosy or reddening appearance to the skin.

It can help to try to think about your symptoms in detail before you visit the doctor because the description you provide can help with your diagnosis.

Causes

If you or your child is complaining of night sweats, you might want to consider recent changes in your environment, as well as whether there are other symptoms, such as fevers, weight loss, pain, or anxiety.

Environment

Your sleeping environment can be causing some or all of your symptoms. This is especially common for young children, who often do not select their own pajamas or blankets. Excessively heavy pajamas, too many blankets on the bed, or a thermostat set at a high temperature can all cause sweating and a feeling of being too hot at night.

Sometimes, the rooms in the house are not all heated or cooled to the same degree, and your child may be sleeping in a room that is warmer than you intended. Sleeping without air conditioning or in a place where you can't adjust the temperature can result in an overly hot room at night.

Medical Conditions

Recurrent sweating at night without an environmental cause is something that you should not ignore. Typically, if your night sweats are caused by a medical condition rather than an environmental cause, your symptoms will not improve by lowering the temperature a few degrees or sleeping with lighter blankets.

The most common medical conditions that can cause night sweats include:

  • Menopause/perimenopause: Altered levels of estrogen and progesterone during menopause and perimenopause interfere with the body's normal temperature regulation. While menopause usually causes hot flashes more often than sweats, it is among the most common causes of sweating at night.
  • Infections: Any infection that causes a high fever, whether a bacterial, viral, or parasitic infection, can make you feel hot and can cause sweating during the day or night. Life-threatening infections, such as osteomyelitis or endocarditis can cause night sweats, and they also cause extreme sweating all the time, jitteriness, vomiting, and overall weakness, often requiring emergency hospitalization.
  • Weight gain/obesity: Weight gain can make you feel hot and can lead to sweating. This is more common during physical activity, and it can be noticeable at night as well.
  • Diabetes: High and low blood sugars can cause sweating all the time, and this can be exacerbated at night due to heavy sheets or pajamas. Diabetes causes hyperglycemia (high blood sugar), and overtreatment of hyperglycemia can result in low blood sugar.
  • Thyroid disorders: Hyperthyroidism usually causes weight loss and agitation, and it is often associated with a feeling of being overheated, potentially resulting in sweating during the day or night.
  • Inflammatory and autoimmune disease: Fevers, inflammation, and intermittent discomfort are all characteristic of autoimmune conditions such as lupus and inflammatory bowel disease. Night sweats and flushing can be a part of the flare-ups.
  • Sleep disorders: Conditions that disrupt sleep, such as restless leg syndrome, nightmares, and sleep apnea, can cause night sweating, often due to tossing and turning.
  • Anxiety: Severe agitation and insomnia at night can cause sweating, sometimes triggered by excessive tossing and turning.
  • Idiopathic hyperhidrosis: Sometimes, people sweat excessively without a known medical cause. This is defined as idiopathic hyperhidrosis and it causes excessive sweating at any time, especially in times of anxiety, and it is often associated with unpleasant body odor.
  • Autonomic disorders: Impairment of the autonomic nervous system can be caused by autonomic neuropathy, spine disease, pituitary disease, and rarely, head trauma or a stroke. Symptoms can include fevers, chills, flushing, and sweating.
  • Tuberculosis (TB): A parasitic infection characterized by cyclic fevers, TB may be recognized based on the complaint of night sweats.
  • Cancer: Most cancers can cause night sweats, but lymphoma and leukemia, which are cancers of the inflammatory white blood cells, are the cancers most typically associated with this. It is important to keep in mind that night sweats are not the only sign of cancer. Cancer produces other symptoms, such as weight loss, fatigue, bleeding, or swelling more often than it causes night sweats.
  • HIV/AIDS: A severe immune deficiency, HIV can cause intermittent sweating, chills, and fevers. These symptoms usually accompany the opportunistic viral infections or cancer that occur due to AIDS, but they can occur even when there is not an obvious viral infection or cancer.
  • Adrenal gland disease (pheochromocytoma): A tumor that causes excessive autonomic nervous system function, a pheochromocytoma can cause sweats and flushing, and it usually also causes a rapid heartbeat, high blood pressure, and anxiety.
  • 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.
  • Drug or alcohol withdrawal: Alcohol and drugs may cause sweating, and withdrawal can cause severe temperature dysregulation, manifesting as fevers or intermittent sweating.

Treatments for some of the above issues may also cause night sweats. For example, hormone therapy—for menopause treatment, or other issues such as fertility problems or cancer—tends to cause more dramatic symptoms than menopause itself because the changes in hormone levels with these drugs tend to be more abrupt.

Several other medications are also associated with night sweats, including antidepressants, chemotherapy, thyroid replacement, and Tylenol (acetaminophen).

A Word From Verywell

Night sweats can interfere with your sleep, resulting in fatigue when you are not well rested. When your child has night sweats, you should try to determine whether there is an environmental cause. If you or your child continues to have night sweats persisting for a week or longer without an obvious environmental cause, you should see your doctor to get an accurate diagnosis and the appropriate treatment.

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