Nine-month-old baby vomiting may be gastritis, intestinal obstruction, respiratory tract infection, intracranial infection and so on. 1. Gastritis: if improper diet, taking drugs, Helicobacter pylori infection, etc., causing gastritis, nausea, vomiting symptoms. 2. Intestinal obstruction: often due to intussusception, inguinal hernia, intestinal torsion, peritoneal inflammation, etc., causing intestinal obstruction, which manifests itself as nausea, vomiting, abdominal pain, abdominal distension, and so on. 3. Respiratory tract infection: especially after the baby coughs violently, it is easy to cause vomiting. 4. Intracranial infections: common ones include purulent meningitis, tuberculous meningitis, viral encephalitis, etc. In addition to vomiting, there are fever, headache, and impaired consciousness. Nine-month-old baby vomiting may also be related to other causes, take your child to the hospital in time to identify the cause of the disease before treatment.