The nerves of a tooth are located in the pulp. The pulp is in the center made up of living connective tissue and cells called odontoblasts. There are two different types of nerve sensitivities.
Pulpal Sensitivity: Nerve pain focused on one specific tooth is most likely affecting the tooth pulp. Common causes of nerve pain in teeth include: a recent tooth filling, tooth decay or infection, pressure from grinding your teeth, cracked, chipped, or broken.
Dentinal Sensitivity: Dentinal sensitivity refers to nerve pain spread throughout different teeth. If the tooth enamel is damaged, eroded away, or external cold, heat, or acid reach the nerve endings in the dentin layer of the tooth, discomfort can occur. Common causes include receding gums, untreated cavities, and teeth whitening.
Contact your dentist as soon as possible if you suffer from nerve sensitivity. The sooner you get it checked, the better!