Foul-smelling sneezes can be caused by nasal diseases, throat diseases, and stomach diseases. If you suffer from nasal diseases such as sinusitis, rhinitis, intranasal papilloma, etc., it may lead to local infection, corruption, nasal cavity due to inflammation stimulation, which causes sneezing with foul smell, the foul smell may come from the local corruption of the tumor or snot. If you suffer from laryngeal diseases such as pharyngeal tumor or chronic pharyngolaryngitis, the above symptoms can be caused by localized erosion and ulceration of the tumor, or such as halitosis, gingivitis, or nasopharyngeal adenoid hypertrophy. If you suffer from Helicobacter pylori infection, chronic gastritis and other stomach disorders, you will also have a bad smell when you sneeze, and it will also be accompanied by acid reflux in the stomach, hiccups, and other conditions that produce a bad smell. If you have persistent bleeding and sneezing odor, it is recommended that you seek medical attention and follow your doctor’s instructions.