Tooth is highly sensitive to heat and cold -- what could be the problem?

Several things: Hot and cold sensitivity can come from several problems. A hole in the tooth , a cracked tooth , a defective filling, a root that is exposed from gum recession are the most common. Have your dentist check it out. It won't go away and it becomes a more expensive to fix later!

Several issues: One, decay, 2 tooth abrasion, 3 clenching and or grinding just to name a few.

Irreversible: Irreversible pulpitis. This means that the pulpal tissue ( nerve, blood vessels) has reached a point of accumulated trauma/irritation from which it is unable to recover. The inflammation is irreversible. See the root canal specialist - the Endodontist - for a thorough evaluation and treatment if needed. You may be lucky and this will recover without tx, but the symptoms are classic. Good Luck.

See a dentist: Teeth can be sensitive for many reasons. If a single tooth becomes sensitive to heat, the tooth's nerve may be dying. See your dentist for diagnosis and treatment if needed.

Thermal Sensitivity: Any number of causes, including but not limited to cavities, loose or cracked filling, cracked tooth, or trauma. Best bet is to see a local dentist for an exam.