Sensitive teeth can cause discomfort when exposed to hot or cold temperatures. This happens because the dentin, a layer beneath the enamel, becomes exposed due to gum recession or enamel erosion. Dentin contains tiny tubules connected to nerve endings, making it sensitive to temperature changes. Common causes include aggressive brushing, acidic diets, tooth grinding, and overuse of whitening products. To alleviate the pain, avoid harsh brushing, limit acidic foods and drinks, and consider using toothpaste designed for sensitive teeth. For severe cases, consult your dentist about bonding treatments.