Night sweats are defined as episodes of excessive perspiration during sleep that are not related to an overly warm environment or heavy bedding. These are different from simply feeling warm and often result in waking up with damp or soaked clothing and linens. Night sweats are a reported and relatively common symptom experienced by many individuals infected with COVID-19.
Night Sweats in Acute COVID-19 Infection
Night sweats emerged as a frequently observed symptom, particularly during the spread of the Omicron and Delta variants of the virus. Reports indicated that this symptom was present in a significant percentage of patients infected with these strains. Unlike typical mild nighttime perspiration, the sweating associated with an acute COVID-19 infection is often described as drenching or profuse.
These episodes can occur even without a high daytime fever. The intense sweating may be accompanied by other common symptoms of acute infection, such as body aches, fatigue, and a sore throat. Recognizing the profuse nature of this symptom helps distinguish it from normal overnight sweating due to environmental factors.
The Body’s Temperature Regulation Response
The appearance of night sweats is a direct result of the immune system’s fight against the SARS-CoV-2 virus. When the body detects a pathogen, immune cells release signaling molecules called pyrogens and cytokines. These chemicals travel to the brain’s hypothalamus, which acts as the body’s thermostat, and effectively raise the temperature set point.
This upward adjustment triggers the body to generate heat, leading to a fever, which is the elevated core temperature intended to create an unfavorable environment for the virus. As the fever peaks or begins to resolve, the hypothalamus lowers the temperature set point back toward its normal range. The body must then rapidly shed the excess heat to meet this new, lower target.
The primary mechanism for this rapid cooling is diaphoresis, or excessive sweating, which efficiently dissipates heat through evaporation. Body temperature naturally fluctuates following a circadian rhythm, often peaking in the late afternoon and dropping at night. Because of this cycle, the body’s cooling response frequently occurs during sleep. This temperature elevation and subsequent rapid drop results in the characteristic drenching night sweats.
Duration and Post-Infection Persistence
For many people, night sweats are a short-lived symptom that occurs during the most acute phase of the illness. Typically, these episodes resolve within a few days or a week as the body successfully clears the active infection. The duration of this symptom is variable, but it often mirrors the timeline of the most intense fever and inflammatory response.
However, for a subset of individuals, night sweats can persist long after the initial infection has cleared, becoming a feature of post-acute sequelae of COVID-19, sometimes referred to as “long COVID.” Studies indicate that persistent night sweats can last for an average of over two months, with some patients reporting the symptom for many months. This prolonged persistence is often linked to ongoing systemic inflammation or dysfunction of the autonomic nervous system, which regulates involuntary functions like temperature control.
Persistent night sweats can significantly disrupt sleep and may be part of a larger cluster of post-viral symptoms. If the excessive sweating continues for several weeks or months after other acute symptoms have vanished, it may indicate a sustained physiological imbalance requiring medical assessment.
Home Management and Medical Consultation
Managing night sweats primarily involves environmental and supportive measures to maximize comfort and reduce the severity of the episodes. Staying well-hydrated is important because profuse sweating leads to a significant loss of fluids and electrolytes. Drinking water or an electrolyte-balanced fluid can help replenish what is lost and support overall recovery.
Adjusting the sleep environment can help mitigate the intensity of the sweats. Keeping the bedroom cool, ideally between 60 and 68 degrees Fahrenheit, prevents unnecessary overheating. Using lightweight, moisture-wicking pajamas and breathable bedding allows sweat to evaporate more easily, reducing the feeling of being drenched. Avoiding known triggers such as alcohol, caffeine, and spicy foods close to bedtime may also help reduce body temperature fluctuations.
Individuals should seek medical consultation if the night sweats are frequent, severe enough to consistently disrupt sleep, or persist for several weeks after the acute infection has resolved. Consult a doctor if the sweats are accompanied by other concerning signs, such as unexplained weight loss, persistent high fever, or chest pain. These accompanying symptoms may indicate an underlying issue requiring specific diagnosis and treatment.