Night sweats are episodes of excessive perspiration during sleep. These episodes are severe enough to drench sleepwear and sheets, often waking an individual. Unlike mild sweating due to an overheated room or too many blankets, true night sweats persist even in a cool, comfortable sleeping environment and are typically caused by internal factors. Understanding their various origins, including connection to illnesses like COVID-19, provides a comprehensive view.
Night Sweats and COVID-19
Night sweats can be a symptom of COVID-19. While fever, cough, and fatigue are widely recognized COVID-19 symptoms, night sweats have been reported by some individuals. They have been noted as a manifestation of different coronavirus variants.
The Omicron variant, for example, has shown night sweats as a distinguishing symptom, with some reports indicating over 40% of infected individuals experienced them. This symptom was not as commonly highlighted with previous COVID-19 variants but became more prevalent with Omicron. Night sweats may even precede other symptoms, and some individuals continue to experience them for months after the initial infection.
Why Illness Can Cause Night Sweats
Illnesses, particularly viral infections like COVID-19, can trigger night sweats as part of the body’s immune response. When the body encounters a pathogen, it initiates a defense mechanism that often includes raising core body temperature, resulting in a fever. This helps create an unfavorable environment for the invading virus or bacteria.
During this immune response, the body releases signaling molecules called cytokines. These cytokines contribute to the inflammatory process and can influence the hypothalamus, the brain region responsible for regulating body temperature. As the body works to fight off the infection, especially during sleep when the immune system is highly active, fluctuations in temperature regulation can occur. This can lead to excessive sweating as the body attempts to cool down, particularly when a fever breaks or changes throughout the night.
Other Reasons for Night Sweats
Night sweats can stem from various causes beyond viral infections like COVID-19, making them a non-specific symptom.
- Medications, including some antidepressants, hormone therapies, and drugs for low blood sugar in diabetes. Certain over-the-counter pain relievers can also contribute.
- Hormonal changes, particularly for women, are a frequent cause. Menopause, pregnancy, or menstrual cycle fluctuations can trigger them. Thyroid conditions like hyperthyroidism also cause excessive sweating.
- Other infections besides COVID-19, such as tuberculosis, HIV, or various bacterial infections like endocarditis.
- Psychological factors like anxiety and stress are linked to night sweats; the body’s “fight-or-flight” response increases heart rate and body temperature, leading to sweating.
- Less common but more serious conditions, including certain cancers like lymphoma, can also manifest with night sweats, often alongside unexplained weight loss.
When to Seek Medical Attention
While occasional night sweats might not indicate a serious problem, consult a healthcare professional if they occur regularly, disrupt sleep, or cause concern. Seek medical attention if night sweats are accompanied by other new or worsening symptoms. These can include unexplained weight loss, persistent fever, a new or worsening cough, or swollen lymph nodes.
It is also important to seek evaluation if night sweats are severe, causing significant discomfort or impacting daily life. Your doctor can help determine the underlying cause and recommend appropriate management or treatment.