Coughing up a grain of very smelly particles in the throat may be food debris or tonsil stones. 1. Food debris: If part of the food remains in the mouth after eating, the food debris embedded in the tonsil crypt for a long time will rot and smell. Food debris may be discharged with coughing, in the form of granules with a foul odor. 2. Tonsil stones: If the tonsils are stimulated by chronic inflammation for a long time, resulting in local tissue adhesions, calcium salt deposits, it is easy to block the tonsil crypts, gradually calcified to form a hard mass, known as tonsil stones. When coughing, tonsil stones may be discharged in the form of smelly particles. This may be accompanied by symptoms such as difficulty in swallowing and a foreign body sensation in the throat. If the coughing up of smelly particles in the throat occurs repeatedly, it is recommended to consult a doctor to clarify the cause of the problem.