Sleeping with a fan on is a common habit, especially in warm weather. For many people, the gentle airflow and background noise make it easier to fall asleep. However, for others, this nightly routine can quietly interfere with sleep quality and overall health.

If you often wake up feeling worse instead of refreshed, your body may be signaling that sleeping with a fan on isn’t the right choice for you. Here are five clear signs to pay attention to.

1. You Wake Up With a Dry Mouth, Throat, or Stuffy Nose
One of the most common signs is dryness in the mouth, throat, or nasal passages when you wake up. A fan constantly circulating air can dry out mucous membranes overnight, reducing their ability to protect against irritation, bacteria, and allergens.

As a result, you may notice:A scratchy or sore throat in the morning
A dry mouth even if you’re well hydrated
Nasal congestion or sinus pressure
This is especially common in people who sleep with their mouth open, have allergies, or already struggle with sinus sensitivity.