The common reasons for a 15-year-old child to eat less and sometimes want to vomit are indigestion, gastritis, lack of micronutrients, etc.; we should find out the reasons in time, and carry out treatment and conditioning for the reasons. 1. Indigestion: 15-year-old children eat very little and sometimes want to vomit, if it is caused by indigestion. If it is caused by indigestion, the doctor can guide the application of drugs such as stomach-enhancing and eliminating food tablets, or the application of drugs to promote gastric power, such as domperidone, which is conducive to improving the above symptoms. 2. Gastritis: 15-year-old children eat very little and sometimes want to vomit, and the symptoms continue not to ease, it is recommended that timely consultation, complete gastroscopy and other examinations, to determine the cause of the disease to be treated, usually pay attention to the structure of the diet, and eating habits. 3. Lack of trace elements: 15-year-old child if due to long-term partiality, picky eating, resulting in the body of trace element deficiencies, especially the lack of zinc, caused by eating very little, sometimes want to vomit. Can be directed by the doctor to apply lysine glucose zinc granules, zinc gluconate oral solution and other zinc supplementation drugs, for the body to supplement zinc, is conducive to make the above symptoms can be relieved. 15-year-old children eat less and sometimes want to vomit, should seek medical treatment as soon as possible, relevant examination, clear cause, give targeted treatment, do not blindly use their own medicine.