Drinking insufficient water

According to Times of India, water helps maintain moisture in the oral cavity and supports saliva production, thereby cleaning food debris. When dehydrated, a dry mouth allows bacteria to accumulate and break down organic matter, producing unpleasant-smelling compounds. Therefore, drinking insufficient water can worsen breath odor, especially in the morning or after prolonged periods without hydration.

Mouth breathing

Mouth breathing often occurs due to nasal congestion, rhinitis, or during sleep. If this habit persists, the constant airflow through the oral cavity can easily dry the tongue's surface and mucous membranes.

Dry mouth reduces saliva's natural cleansing ability, creating an environment for odor-causing bacteria to flourish. Consequently, some individuals often wake up with bad breath despite brushing their teeth before bed.

Eating onions and garlic often causes bad breath. Photo: Kim Uyen

Eating strong-flavored foods

Heavily spiced dishes containing ingredients like onion, garlic, pepper, and chili can cause bad breath after consumption. Specifically, onions and garlic contain odor-producing compounds; after digestion, some of these compounds enter the bloodstream, travel to the lungs, and are then expelled during breathing. Brushing or rinsing the mouth cleans the oral cavity but does not immediately eliminate this odor.

Prolonged fasting

Fasting or frequently skipping meals also impacts breath. When not eating for extended periods, chewing activity and saliva production decrease, making the oral cavity drier.

When the body lacks energy from food, especially during strict diets or very low carbohydrate intake, it increases fat utilization for energy. This process produces ketones, some of which can give breath a distinct odor, according to Eating Well.

Inadequate oral hygiene before sleep

During the day, food and plaque constantly accumulate in the oral cavity. If teeth are brushed superficially in the evening or interdental spaces are not cleaned, these substances can persist for hours.

At night, saliva production decreases compared to daytime, creating conditions for bacteria to grow and cause odor. Consequently, breath often smells worse upon waking. Thorough brushing, interdental cleaning, and tongue hygiene before sleep help mitigate this situation.

Le Nguyen (Compiled)