A foul taste in the throat can be caused by dietary factors, tonsillitis, tonsil stones, sinusitis and other reasons. 1. Dietary factors: If you eat food with a foul odor, such as durian, snail powder, stinky tofu, etc., the foul odor of the food itself will remain in the throat for a short time, resulting in a foul taste in the throat. 2. Tonsillitis: If the tonsils are infected with pus, the purulent secretions are retained on the surface of the tonsils or in the tonsillar crypts, which may cause a foul taste in the throat. 3. Tonsil stones: inorganic salt deposits that occur in the tonsil crypts. When the stones are small, there may be no obvious discomfort. When the stones are large, there may be symptoms of bad breath, which may be rotten egg taste bad breath, and no improvement after gargling. 4. Sinusitis: sinus infection, purulent secretion secretion through the nasal passages can flow back into the nasopharynx, oropharynx, throat will sometimes feel a foul taste. The most important thing is to pay attention to the oral hygiene in normal life. Throat has a foul taste, exclude dietary factors, it is recommended that the hospital consultation, diagnosis and treatment.