Why are my teeth sensitive?

Tooth sensitivity is exposed inner structure: under the enamel lies dentin, a layer full of microscopic tubes running to the nerve, and when dentin loses its cover - enamel worn thin or gums receded - cold, hot, sweet, or acidic things zap the nerve. The ADA lists the usual causes: brushing too hard or with a stiff brush, acidic drinks and reflux softening enamel, grinding at night, receding gums, recent whitening, a cavity, or a cracked tooth. The good news: most sensitivity is fixable at the drugstore level first. Desensitizing toothpaste - with potassium nitrate or stannous fluoride - genuinely works, but needs two to four weeks of twice-daily use; apply, spit, do not rinse. Switch to a soft brush, ease the pressure, and cut acidic drinks or use a straw. Whitening-related sensitivity usually fades when you pause the whitening. See a dentist when: one tooth is sharply sensitive while the rest are fine - that pattern suggests a cavity or crack, not general wear; sensitivity started suddenly or is getting worse; or pain lingers after the cold is gone, which points deeper toward the nerve. A dentist can seal exposed roots, apply fluoride varnish, or treat the cavity - all quick, all cheaper than waiting. Pymander is a free AI doctor, 24/7 by text. Describe which teeth and what triggers them, and it can help you prep for the dentist.