Major causes of a toothache include tooth decay, tooth fracture, infected gums, an abscessed tooth and a damaged filling. These causes can lead to constant tooth pain, fever, and swelling around the tooth, says WebMD.
Of all the causes of a toothache, tooth decay is the primary one. When a person eats foods high in starches and sugars, bacteria in the mouth turn food particles that remain trapped in the teeth into acids. These bacteria then form a plaque that clings to the teeth, dissolving the enamel and creating cavities. Tooth decay may lead to an abscessed tooth, characterized by a painful infection between a tooth and the gum or at the root of a tooth, notes WebMD.
Gum disease is also very common and results from the growth of bacteria in the mouth. If left untreated, it can destroy the tissue that surrounds the teeth and later cause tooth loss, reports WebMD. Also, sinuses may become inflamed due to a bacterial, fungal or viral infection in the sinus cavity, causing pain in the upper teeth, according to Healthline. Ways of reducing a toothache include rinsing the mouth with warm water, removing food particles with dental floss, and applying oil of cloves or an antiseptic containing benzocaine to the affected area, says Mayo Clinic.