What Causes Night Sweats? 8 Reasons to Consider

    Published 20 January 2020
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    Reviewed by Olga Adereyko, MD, Primary Care Physician, General Practitioner, Medical Consultant
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    It’s not unusual for you to wake up in the middle of the night feeling sweaty. Maybe your comforter’s too thick, or your A/C is set too low. But extreme night sweats and frequent sweating at night while sleeping could indicate a larger issue. Next, we dive deeper into the multiple causes of night sweats, how to stop night sweats, and when to be concerned about night sweats.

    What is considered excessive sweating?

    First, what are night sweats? Night sweats are repeated episodes of excessive sweating while sleeping. You spontaneously begin to perspire, sometimes soaking right through your pajamas and sheets.

    Sweating is a routine body function designed to dispel excess heat and regulate your body temperature. If your room feels comfortable and you’re not overdoing it with the bedding, then your night sweats may be attributed to illness, hormonal shifts, or medication. 

    What causes night sweats?

    There are countless explanations for what causes night sweats. Some night sweat causes seem unavoidable, such as those linked to menopause. But if this doesn’t apply to you, then read on for more possible answers to the question, “Why do I sweat when I sleep?”

    1. Menopause

    Menopause is a common cause of night sweats for women. As you get older, your body no longer produces the same amount of hormones it used to. As these levels change and settle into a new pattern, your body experiences various symptoms, cold sweats at night being one of them.

    Estrogen and progesterone undergo the greatest change during menopause. These two hormones, along with others, control your body temperature. Since you’re currently going through hormonal surges, your temperature will also surge ‒ producing night sweats. You might feel very cold one minute and very hot the next. 

    Sweating while sleeping can be a regular occurence when you’re menopausal. Try taking steps to alleviate your symptoms, such as:

    • Keeping a fan by your bed: Have one nearby so you can quickly and easily turn it on in the middle of the night. 
    • Placing the A/C remote on your nightstand: Avoid having to climb out of bed while you’re half asleep just to adjust the thermostat. 
    • Staying hydrated: Excessive perspiration means a lot of water is lost in a short amount of time. If you’re sweating at night, replenish yourself accordingly.
    • Changing your bedding: Choose stay-cool linens, like silk pillowcases and bed sheets. Also note that memory foam mattresses trap body heat, so it’s wise to switch to a regular mattress during menopause. 
    • Talking to your doctor: If sweating at night is really disrupting your sleep routine, a medical professional could suggest certain therapies to offer relief from menopause-related night sweats.

    2. Stress

    One of the biggest night sweat causes is stress. Anxiety, long work hours, and a lack of sleep inevitably lead to stress, which in turn, causes sweating. 

    Your body tends to perspire more when it’s under both physical and mental stress. Immediately after being in a physically stressful situation, you probably feel the need to cool off and relax. When enduring mental stress, your mind remains in this agitated state after you fall asleep, and is likely the reason behind what causes night sweats.

    Try these tips for reducing stress levels:

    • Practice yoga: Allow your body to stretch and realign itself with a daily session of relaxing yoga. 
    • Lighten your workload: Work is important, but so is your well-being. Try to rearrange your schedule so it better suits your needs and offers a bit more breathing room.
    • Get plenty of rest: Sometimes our minds get stuck in a constant state of exhaustion due to lack of sleep. Lock in at least 8 to 10 hours of sleep each night.
    • Do deep breathing exercises: It thoroughly soothes both your body and mind. Take a few minutes in the morning to breathe deeply and start your day off right.

    3. Hormonal disorders

    Much like menopause, hormonal disorders interfere with your natural hormone patterns and create sweating at night. If certain patterns become disrupted, your body temperature will become erratic. Consult your doctor to see if you might have one of the following conditions:

    • Hyperthyroidism
    • Pheochromocytoma

    They can determine whether this is the reason you’re sweating while sleeping.

    4. Hypoglycemia

    Hypoglycemia, a shortage of glucose in the blood, occurs when your body is unable to control its blood sugar levels. This prevents it from functioning the way it’s supposed to. 

    Low glucose triggers the release of adrenaline, which in excessive amounts, produces a great deal of perspiration. Individuals with hypoglycemia or who take insulin or diabetes medications usually display lower glucose levels, and are prone to sweating at night.

    If you’ve been diagnosed with hypoglycemia and notice frequent night sweats, leave a few glucose tablets or a snack on your nightstand. Once your blood sugar levels return to normal, the sweating should stop.

    5. Certain medications

    Some medications come with side effects, ranging from manageable to extreme. Each individual can respond differently to the same drug. Though it’s intended to relieve specific symptoms and promote healing, it might do so by interfering with your body’s natural (including hormonal) processes. As such, a common side effect of certain medications is hot flashes and cold sweats at night. 

    So if you’re experiencing night sweats, discuss these symptoms with your doctor, who may decide to adjust your medication. 

    6. Infections

    Occasionally, your body produces night sweats because it’s trying to heal itself. When you develop an infection, your temperature rises in an attempt to kill the bacteria or virus that’s making you sick. 

    If the infection is serious, your body could continue to increase its temperature, resulting in fevers, hot flashes, and night sweats. Infections known to cause night sweats include:

    • Tuberculosis
    • HIV
    • Influenza
    • Other febrile illnesses (any illness that causes a fever)

    The presence of any of these illnesses is a potential cause of night sweats. Consult your doctor, who might prescribe medications for addressing your frequent night sweats and other symptoms.

    7. Sleep apnea

    Studies show that individuals with sleep apnea, especially if left untreated, are three times more likely to have cold sweats at night. Sleep apnea occurs when your throat narrows as you sleep, which obstructs your airways. Your body often responds to this condition by heating up and producing night sweats. 

    Consider talking to your doctor, who can prescribe a sleep apnea treatment that provides relief from night sweats.

    8. Idiopathic hyperhidrosis

    Idiopathic hyperhidrosis causes extreme perspiration and night sweats, with little to no underlying illness or explanation. In rare cases, however, one reason behind having night sweats is the presence of Hodgkin’s lymphoma. It’s a cancer of the lymphatic system, which is part of your body’s immune system. 

    When to see a doctor

    If you’re unsure of when to be concerned about night sweats, start by ruling out any environmental causes, such as:

    • Temperature: Make sure your bedroom thermostat is set to a comfortable temperature for sleeping (and preventing night sweats).
    • Bedding: Remove any extra blankets or comforters, and only buy mattresses made from breathable materials.
    • Exercise: Avoid working out right before bed as it can increase your body temperature.
    • Spicy foods: Steer clear of hot wings, three-alarm chili, or anything super spicy before bedtime. Otherwise, you can expect both night sweats and possible indigestion. 

    Next, keep track of any recurring night sweats by writing them down in a journal. If night sweats persist after you’ve made these changes, this could point to a health condition. It might be time to see a doctor and undergo certain tests to determine the exact cause of night sweats. Seek advice if you experience:

    • Night sweats that regularly wake you up 
    • Very high temperature (or if you feel hot or shivering)
    • Cough or diarrhea
    • Night sweats accompanied by unexplained weight loss

    Despite being uncomfortable, night sweats shouldn’t be a source of ongoing frustration for you. Talk to your doctor about how to stop night sweats, and they’ll work with you to find the right night sweat treatment to help you achieve more restful sleep.

    History of updates

    Current version (20 January 2020)

    Reviewed by Olga Adereyko, MD, Primary Care Physician, General Practitioner, Medical Consultant

    Published (20 January 2020)

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