Morning breath occurs because your mouth drastically reduces saliva production while you sleep, creating the perfect anaerobic environment for bacteria to absolutely thrive.

A closer look

Morning breath occurs because your mouth drastically reduces saliva production while you sleep, creating the perfect anaerobic environment for bacteria to absolutely thrive. During the day, your saliva constantly washes away food particles and dead cells, but at night, your mouth basically turns into a stagnant swamp of decomposing biological matter. These microscopic squatters feast on the proteins left behind in your oral cavity and excrete volatile sulfur compounds, which is exactly why your breath smells like a tragic mix of rotting cabbage and despair when you wake up. You can brush your teeth religiously for twenty minutes before bed, but you cannot stop the fact that your mouth is essentially a 24-hour all-you-can-eat buffet for germs that repay your generous hospitality by making you completely unkissable before your first cup of coffee!