Night Sweats – What Causes Them in Men and Women?

What is Night Sweats?

Sweating is an automatic mechanism of our body. It is triggered by hormone secretions from our brain, specifically the parasympathetic nervous system.

A cascade of reactions then causes our sweat glands, located under the skin all over the body, to start sweating.

Excessive sweating is when this sweating becomes truly bothersome, in excessive amounts, or at inconvenient times.

And it can occur at night, during sleep: these are night sweats. They can disrupt sleep and decrease quality of life.

Why focus on the causes of night sweats?

It is important to understand the causes of night sweats because they can be a sign of an underlying health problem, such as:

• an infection,
• an endocrine or cardiovascular disease,
• the side effect of a medication.

By understanding the causes, it is easier to effectively treat the underlying cause and hope to decrease or eliminate this nighttime sweating.

Moreover, sweating has been studied for several decades, in animals as well as humans.

And there are even scientific publications specifically on these problems of night sweats.

I will now present in detail the 3 major causes of excessive sweating occurring at night:

1. diseases,
2. medications,
3. diet or lifestyle.

Causes of Night Sweats Related to Diseases

Here are the main pathologies known to cause night sweats.

1. Hyperhidrosis. When a person frequently sweats excessively, they may have primary hyperhidrosis: this sweating is not related to a disease but is of genetic origin. This is the condition I discuss the most on this site, the Hyperhidrosis Observatory. 💦
2. Menopause. This is not strictly a disease but rather a physiological change in women. With significant hormonal changes, triggering the famous hot flashes and sweats, both during the day and at night. 🌡️
3. Infections. Some infections, such as tuberculosis and typhoid fever, can cause night sweats. Night sweats are often associated with other symptoms such as fever and fatigue. 🦠
4. Diabetes. Diabetes can cause night sweats due to fluctuations in blood sugar during the night, regulated by hormones. People with diabetes may also experience excessive thirst and the need to urinate frequently. 🩸
5. Heart diseases. Heart diseases such as angina and heart failure can cause night sweats due to increased pressure on the heart. Patients may also experience chest pain and shortness of breath. ❤️
6. Cancer. Some cancers, such as lung cancer and lymphoma, can cause night sweats due to increased hormone production by tumors. Cancer patients may also experience weight loss, fatigue, and pain. See my article on excessive sweating in cancer patients. 🎗️
7. Sleep disorders: narcolepsy, obstructive sleep apnea, insomnia, restless legs syndrome/periodic limb movement disorder during sleep. (Idiaquez 2022) 😴
8. Mental illnesses. Mental disorders such as anxiety and depression can cause night sweats due to the response to emotional stress. Patients may also experience insomnia, palpitations, and anxiety. 🧠

As you can see, these pathologies (except primary hyperhidrosis) present other symptoms. So, there is not much reason to worry about having another disease if you only suffer from excessive sweating, although you can of course discuss it with your doctor to clarify things.

Causes of Night Sweats Related to Medications

Another common cause of night sweats is the occasional or regular consumption of medications.

1. Antidepressants. Some antidepressants, such as venlafaxine and paroxetine, can cause night sweats due to their effect on neurotransmitters in the brain. Night sweats are often associated with other symptoms such as fatigue and drowsiness. See my more detailed article on antidepressants and night sweats. 😔
2. Blood pressure medications. Some blood pressure medications, such as beta-blockers, can cause night sweats due to their effect on blood circulation. Patients may also experience dizziness and fatigue. 💓
3. Nonsteroidal anti-inflammatory drugs (NSAIDs). Some NSAIDs, such as ibuprofen and naproxen, can cause night sweats due to their effect on prostaglandins in the body. Patients may also experience joint pain and headaches. 💊
4. Sleep medications. Some sleep medications, such as Ambien and Lunesta, can cause night sweats due to their effect on neurotransmitters in the brain. Patients may also experience insomnia and nightmares. 😴

It is somewhat easier to identify if night sweats are related to a medication compared to when they occurred: before or after the start of treatment?

However, some medications like antidepressants should not be abruptly stopped as the risk of side effects is high.

Causes Related to Diet or Lifestyle

Here are some factors related to diet and lifestyle that can cause night sweats.

1. Alcohol consumption. Alcohol consumption can lead to dilation of blood vessels, which can cause night sweats. Additionally, alcohol can interfere with sleep cycles and brain function, which can also contribute to night sweats. I discuss this in detail in an article on excessive facial sweating and alcohol (coming soon in english). 🍷
2. Tobacco or cannabis. Tobacco consumption can cause night sweats due to the stimulating effect of nicotine on the nervous system. Smokers may also suffer from lack of sleep, heart palpitations, and nighttime coughing. I’ve dedicated a full article to the effect of THC and cannabis on sweating. 🚬
3. Caffeine consumption. Caffeine can cause night sweats due to its stimulating effect on the nervous system. People consuming large amounts of caffeine may also suffer from insomnia, anxiety, and heart palpitations. ☕
4. Late meals. Late meals can cause night sweats due to their effect on digestion and nutrient absorption. People consuming large amounts of food late in the evening may also suffer from bloating, heartburn, and nighttime awakenings to use the bathroom. 🍽️
5. Stress and anxiety. Stress and anxiety can cause night sweats due to their effect on hormone levels and brain function. People experiencing stress and anxiety may also suffer from insomnia, heart palpitations, and nighttime coughing. 😰

Diet and lifestyle can also be the cause of occasional night sweats (such as after a heavy drinking session) or more frequent ones.

When to Worry About Night Sweats in Women?

If you’re a woman nearing menopause, in menopause, or just post-menopause, night sweats are more the norm than a cause for concern. They are linked to hormonal fluctuations during this stage of life, often marked by hot flashes.

They should gradually subside over time. You can, of course, discuss them with your primary care physician during your next visit, who can reassure you.

If you’re a woman further from menopausal age, and these night sweats suddenly appear out of nowhere for several days, then discussing them with your doctor seems appropriate.

As I explained, night sweats are rarely the main sign of an underlying disease requiring specific treatment. But again, your doctor can reassure you and prescribe further tests if necessary.

When to Worry About Night Sweats in Men?

Men are less likely to experience night sweats.

Again, if your night sweats suddenly appear out of nowhere and last for several days, you can consult your primary care physician to assess the situation.

Simply sweating excessively at night is not indicative of a specific pathology. By examining you and asking questions, your doctor can differentiate between the various possible causes of this sudden excess sweating.

Conclusion: Why Do We Sweat at Night?

Night sweats can be caused by many different factors, ranging from illnesses and medications to dietary habits and lifestyle. It’s important to consider all the factors that may influence your health to determine the cause of your night sweats.

You can take steps to improve your sleep quality and overall health, such as reducing stress, regular exercise, healthy eating, and limiting alcohol and caffeine consumption. Using sheets that help reduce sweating is also an option.

Here are two examples:

• DOZ by SIJO 100% Organic Bamboo Sheet Set (see on Amazon)
• Oeko-Tex Bed Sheet Set Cotton (see on Amazon)

By taking care of your body and health, you can minimize the risk of night sweats and lead a more comfortable and peaceful life. You’ll find many articles on the Hyperhidrosis Observatory blog to assist you in this regard!

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Still have questions, remarks, or advice to share? They are welcome in the comments🙂!

You may also like:

• 8 Facts About Sweating at Night
• Why I Sweat a Lot for No Reason?
• Medication for Hyperhidrosis

 📚 SOURCES

Idiaquez J, Casar JC, Arnardottir ES, August E, Santin J, Iturriaga R. Hyperhidrosis in sleep disorders – A narrative review of mechanisms and clinical significance. J Sleep Res. 2022 Jun 15:e13660. doi: 10.1111/jsr.13660. Epub ahead of print. PMID: 35706374.

Les médicaments qui causent la transpiration excessive. Dermnet, ici (en anglais)

L’hyperhidrose primaire et secondaire selon SweatHelp, principale association sur l’hyperhidrose (en anglais) : ici

Synthèse des connaissances scientifiques, en 2021 sur l’hyperhidrose, en anglais : ici

Collercandy N, Thorey C, Diot E, Grammatico-Guillon L, Thillard EM, Bernard L, Maillot F, Lemaignen A. When to investigate for secondary hyperhidrosis: data from a retrospective cohort of all causes of recurrent sweating. Ann Med. 2022 Dec;54(1):2089-2101. doi: 10.1080/07853890.2022.2102675. PMID: 35903938; PMCID: PMC9455328.