The causes of nausea and vomiting in a car include motion sickness, early pregnancy reaction, gastrointestinal diseases and so on. 1. Motion sickness: this disease is caused by the vestibular function is too sensitive, when riding in the car will appear nausea, want to vomit, accompanied by dizziness and other symptoms. Oral motion sickness medication can be taken as prescribed by the doctor for symptomatic treatment, and the representative medications include phenylephrine, scopolamine, and so on. 2. Early pregnancy reaction: in the early stage of pregnancy, due to hormonal changes in the body and the symptoms of dizziness, nausea, vomiting, due to the bumps in the car, can make the above symptoms worse. It is recommended to eat small meals, eat easy-to-digest food to reduce the burden on the gastrointestinal tract, and generally can be relieved in the middle and late stages of pregnancy. 3. Gastrointestinal diseases: Indigestion can occur when suffering from gastrointestinal diseases. When riding in a car, due to the special odor and bumps in the car, patients may have nausea, want to vomit and other symptoms. When the symptoms of dizziness, want to vomit, longer duration or symptoms can not be relieved, should consult a doctor in time to avoid delaying the condition.