Tongue Coating

A coated tongue is the visible accumulation of keratin, food debris, bacteria and shed cells between the small papillae on the tongue surface. It is common on waking, more noticeable with mouth breathing, dehydration, smoking, a soft diet, poor oral hygiene, and reduced saliva - which is why it often accompanies medications that dry the mouth. In most cases it is cosmetic and harmless, and it responds within days to better hydration, gentle tongue cleaning with a scraper or soft brush, and treating any nasal blockage causing mouth breathing. What matters is distinguishing simple coating from things that look similar. Oral thrush produces creamy white patches that can be scraped off leaving a red base, is common after inhaled corticosteroids or antibiotics, and needs antifungal treatment. Oral leukoplakia produces white patches that do not scrape off and require dental assessment because a minority carry premalignant change. Geographic tongue creates migrating map-like patches and is benign. A black hairy tongue reflects overgrown papillae, often after antibiotics, bismuth or smoking. Supplement evidence is minimal; correcting B12, iron or folate deficiency helps where the tongue is sore or smooth rather than coated.