Vomiting after bathing may be due to hypoxia, insufficient blood supply to the brain, dehydration, hypoglycemia and other reasons. 1. Hypoxia: when patients take a bath, they are in a closed bathroom for a long time, and if they take a bath for a long time, they will consume the oxygen in the bathroom, which reduces the oxygen supply to the brain and leads to the symptoms of nausea and vomiting after taking a bath. 2. Insufficient blood supply to the brain: when the patient takes a bath, the blood will flow to the surface of the body, so that the blood pressure is lowered, the blood supply to the brain is insufficient, and nausea and vomiting symptoms occur after taking a bath. 3. Dehydration: When the patient takes a bath, due to the heat of the confined space, slight dehydration may occur, resulting in a decrease in the patient’s blood volume, nausea, vomiting and other symptoms. 4. Hypoglycemia: When patients suffer from hypoglycemia, if they go to the bathroom to take a shower, it will lead to energy consumption and aggravate the symptoms of hypoglycemia, which will make the patients suffer from dizziness, nausea, vomiting and other symptoms. Patients who vomit after taking a bath may have other causes besides those mentioned above. Patients can go to the hospital for examination, and if there is a disease, they can follow the doctor’s advice for treatment.