Why do I get a dry mouth at night?

Saliva production naturally dips at night, so anything that dries you further announces itself by 3am. The NHS lists the main causes, and the first is the most common: breathing through your mouth at night, which happens when your nose is blocked or you sleep with your mouth open - hours of airflow over the tongue wicks moisture away. Second is dehydration, from not drinking enough, sweating a lot, or being ill. Third is medicines: check the leaflet, because dry mouth is a listed side effect of many common ones - MedlinePlus names some medicines for high blood pressure, depression, and bladder control specifically. Evening alcohol and caffeine both dehydrate, and heated bedrooms dry the air you breathe. This is worth fixing rather than enduring: saliva does more than keep your mouth comfortable - it protects your teeth, and MedlinePlus notes dry mouth raises the risk of tooth decay and mouth infections, which is why chronic dry mouth turns into dental trouble. The fixes map to the causes: treat the blocked nose (saline rinse, allergy spray if relevant), water within reach at night but the real work is daytime hydration, humidify a dry bedroom, ease off evening alcohol, and review your medicine leaflets. A pharmacist can suggest saliva substitutes and sugar-free gum or pastilles to stimulate flow in the day. See a GP if self-help fails, if dry mouth arrives with very dry eyes (that pairing gets investigated), or with constant thirst and frequent urination - diabetes announces itself that way. Pymander is a free AI doctor, 24/7 by text, that can help you find your cause.