Night Sweats: Common Causes and When to Be Concerned

Night sweats are a common occurrence affecting many individuals irrespective of age and gender, and they are characterised by excessive sweating during sleep. Individuals often worry about their underlying cause, making it a frequent complaint to health care providers. While occasional sweating while sleeping may be nothing to worry about, chronic or excessive sweating while asleep could signal an underlying health issue.   

Overview 

Sweating is a natural way for the body to cool down when its core temperature rises above a certain thermos-neutral zone. Night sweats, also known as nocturnal hyperhidrosis, are intense and uncomfortable episodes of excessive sweating, leaving the clothing and bedding completely soaked with sweat. Night sweats are not simply caused by a warm sleeping environment. Rather, they can be linked to underlying factors such as hormonal changes, infections and even certain medications. Studies reveal that night sweats affect up to 401% of primary care patients, with the highest occurrence among individuals between 41 and 55 years of age. 

How do night sweats differ from normal sweating? 

Regular nighttime sweating typically happens due to environmental factors such as warm bedroom temperature, spicy food consumption at nighttime and heavy bedding or wearing thick pants. However, some may also experience night sweats in winter, which may feel surprising, but it often has less to do with external temperatures and more with internal body processes. Even in cold weather, the body may sweat excessively at night due to various factors, which include medications affecting the nervous system or sweat glands, sleep stage disturbances, autonomic nervous system disorders and certain metabolic abnormalities.  

True night sweats stand apart from regular perspiration. During an episode, people often experience sudden waves of heat throughout their body, accompanied by reddening skin and a rapid heartbeat. Additionally, night sweats frequently disrupt sleep patterns and can lead to waking up in cold, damp clothing. 

When to be concerned? 

Medical attention becomes necessary under several circumstances. Be careful in case of any of the following issues: 

• Regular episodes that consistently disturb your sleep  
• Night sweats accompanied by unexplained weight loss 
• Episodes occurring alongside high fever, chills or persistent cough  
• Drenching sweats that happen frequently despite sleeping in a cool environment 

Research indicates that although night sweats alone don’t suggest an increased mortality risk 3, they significantly impact quality of life. Furthermore, only 12% of patients voluntarily report night sweats to their physicians without being explicitly asked. 

Night sweats often correlate with other health indicators. People experiencing these episodes frequently report: 

• Daytime fatigue 
• Additional sleep-related symptoms 
• Waking with a bitter taste in the mouth 
• Obstructive sleep apnea 
• Anxiety 
• Respiratory symptoms  

What causes night sweats? 

Reasons for night sweats can be triggered by a variety of factors. Some of these factors include: 

• Hormonal changes: Fluctuations in hormonal changes can cause night sweats, especially in women. Reproductive hormones like oestrogen and progesterone can lead to uncomfortable shifts in body temperature, making one feel overheated. Symptoms such as hot flashes or excessive sweating while sleeping might trigger to cool down the overheated body. 
• Perimenopause and menopause: The symptoms of night sweats are common during perimenopause and menopause. During this time, your ovaries produce less oestrogen, progesterone and testosterone, resulting in irregular periods. The fluctuating hormone levels during perimenopause and menopause can cause the hypothalamus to malfunction. This glitch in the body’s internal thermostat can lead to sudden warmth or flushing in your face, neck and chest, prompting to cool the body from excessive sweating. 
• Premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD): Hormonal fluctuations during your menstrual cycle can lead to night sweats. Oestrogen levels decrease before your period, a time commonly associated with PMS and PMDD. While irritability and cramps are more typical symptoms, night sweats can also occur. 
• Pregnancy: Hormonal changes during pregnancy may cause night sweats, particularly during the first trimester (weeks 1 to 14) and the third trimester (weeks 27 to childbirth). These night sweats may continue for a few weeks postpartum as your hormones return to pre-pregnancy levels.  

What is the cause of night sweats in males?  

While hormonal fluctuations are one of the reasons for night sweats in women, men also experience hormone changes, such as low testosterone levels, that may cause night sweats. Night sweats can also be triggered by many factors in both males and females, irrespective of age and gender. These causes include: 

Underlying health conditions: 

• Infections: Certain infections, such as tuberculosis, endocarditis or HIV, can cause night sweats as the body right off the invading pathogens.  
• Sleep disorders: Obstructive sleep apnoea disrupts normal sleep patterns and causes excessive sweating. 
• Digestive issues: Gastroesophageal reflux disease (GERD) shows a notable connection to night sweats. 
• Cancer: Certain cancers, particularly leukaemia and lymphoma, might present with night sweats symptoms. Cancer treatment, specifically chemotherapy and radiation therapy, likewise triggers excessive nighttime sweating. 
• Neurogenic conditions: Autonomic dysreflexia, stroke and damage to autonomic nerves can result in night sweats. 

Medication side effects: Drug-induced hyperhidrosis is one of the side effects of certain medication classes. These include: 

• Antidepressants: Antidepressant drugs, such as selective serotonin uptake inhibitors, affect serotonin levels, which potentially trigger sweating episodes. 
• Pain medications: Opioids and common pain relievers can cause sweating through rebound effects. 
• Other notable medications: These include corticosteroids, hormone therapy medications, blood pressure medications and diabetes treatments. 

Medications can increase sweat production and alter body odour, but drug-induced hyperhidrosis does but always cause unpleasant smells. Individuals experiencing medication-related night sweats should consult their healthcare providers for potential alternatives instead of stopping medications on their own. 

• Lifestyle factors: Daily habits and lifestyle choices play a crucial role in triggering night sweats. Common factors include:  
• Diet and drinking habits: Consuming spicy foods can trigger the nervous system and increase body temperature. In addition, consuming alcohol can also lead to increased perspiration. 
• Exercise timing: Physical activity timing significantly impacts nighttime sweating patterns. High-intensity evening workouts can disrupt sleep patterns. Vigorous exercise close to bedtime raises body temperature and stimulates the sympathetic nervous system, making it harder to wind down.  
• Bedroom environment: Sleeping environment influences sweating patterns. Certain bedding materials, such as memory foam mattresses, thick sheets and tight-fitting clothes can contribute to overheating. 

Treatment  

Common treatment options include: 

• Medical treatments: These include Hormone replacement therapy and antidepressants  
• Natural remedies: Natural approaches include consuming herbal supplements such as Black cohosh and red clover. However, their efficiency in this aspect is still being debated. 
• Body-cooling techniques: These include cool showers before bedtime, cooling mattress toppers with heat-absorbing materials and specialised cooling pillows. 
• Environmental adjustments: Ensure proper ventilation and maintain bedroom temperature between 65–70 °F. 
• Dietary modifications: Limit alcohol consumption and choose foods that maintain stable blood sugar levels. Include lean proteins, fresh fruits and vegetables in your diet. 

Conclusion 

Occasional night sweats are common while persistent asleep with night sweats warrant a visit to a healthcare provider for further evaluation. By identifying the underlying cause, appropriate treatment can be initiated to elevate night sweats symptoms and improve overall quality of life.