Hiccups with bad smell may be related to daily diet, and may also be caused by indigestion or Helicobacter pylori infection. 1. Daily diet: after consuming foods with strong irritating odor, such as stinky tofu, green onion, garlic, etc., the bad smell will appear when burping, which is usually temporary and can disappear on its own without any other treatment. 2. Indigestion: Eating a lot of greasy and indigestible food may cause indigestion, food in the gastrointestinal tract for a long time, can not be completely digested, produce a lot of odor gas, the phenomenon of burping odor, may also be accompanied by nausea and vomiting and other symptoms. 3. Helicobacter pylori infection: when there is Helicobacter pylori infection in the digestive tract, it may cause damage to the mucous membrane of the gastrointestinal tract and affect the gastrointestinal function, which will lead to burping with bad smell and bad taste in the mouth. If the burp smells bad and is accompanied by other abnormalities, it should be alerted to disease factors, and it is recommended to consult a doctor for examination and treatment.