Why Sleeping with a Fan On Might Be Harming Your Health

A doctor has warned that sleeping with a fan running all night could lead to coughing fits, chest discomfort, and painful muscle tension.

US-based physician Dr Naheed Ali explains that while fans are often used to stay cool, especially during heatwaves, they can quietly strain the body. Constant airflow can irritate the throat and airways, while also reducing blood flow to muscles, he says.

Hidden Risks, Especially for Allergy and Asthma Sufferers

For those with allergies or asthma, the risks may be even more serious. Fans can circulate dust, dirt, and other allergens through the air, making symptoms worse.

“People with asthma allergies often wake with extra chest tightness after a night with the fan on,” Dr Ali noted.

His comments come just as parts of the UK prepare for a potential heatwave, with temperatures forecasted to hit up to 30°C by Thursday, according to the Met Office.

Dryness and Irritation in the Airways

While fans can help people get to sleep—since the ideal room temperature for rest is between 16°C and 18°C—Dr Ali cautions that prolonged exposure to moving air can dry out the nasal passages and throat.

“The steady airflow of the fan can leave the nasal passages and throat uncomfortably dry by morning,” he told LADbible.

Dry air can lead to thicker mucus in the nose and sinuses, and increased phlegm in the throat, which can cause congestion and discomfort.

“A dry airway produces thicker mucus, which can trap allergens and irritants close to sensitive tissue,” Dr Ali explained. “Over time, this may trigger coughing, a scratchy voice, or clogged sinuses that linger throughout the day.”