Why Do Some People Sleep With Their Mouth Open?

By Vanshika Gaur
12 Jun 2025, 19:30 IST

Many people sleep with their mouth open without even realising it. This common sleep habit can be linked to numerous physical or medical reasons. Here are a few possible causes behind sleeping with your mouth open. Tap to know!

Blocked Nasal Passages

Some individuals may sleep with their mouth open due to nasal congestion or blockage from colds, allergies, or sinus infection.

Sleep Apnoea

People with obstructive sleep apnoea often breathe through the mouth due to interrupted airflow during sleep.

Enlarged Tonsils

In some individuals, enlarged tonsils can narrow the airway, potentially leading to mouth breathing while sleeping.

Allergies

Allergic reactions can also swell nasal tissues, restricting airflow and leading to mouth breathing while sleeping.

Deviated Nasal Septum

A misaligned nasal septum can block airflow in one or both nostrils, resulting in open-mouth breathing.

Poor Sleep Posture

Sleeping on your back can cause the jaw to relax and fall open, especially if the nasal passages are partially blocked, leading to mouth breathing while sleeping.

Information Credits

According to PubMed, people sleep with their mouths due to blocked nasal passage, sleep apnoea, and more. It is advisable to consult a healthcare professional for personalised suggestions.