First, read the English article below.

A very common cause of vomiting is gastroenteritis, an inflammation of the gastrointestinal tract which, while painful, is not a serious medical condition. The nausea lasts for more than a few days or there is a possibility of pregnancy. Personal treatments are not effective, you suspect dehydration, or a known injury has occurred, causing vomiting. Vomiting lasts for more than a day, or accompanying diarrhea lasts for more than 24 hours. For infants, vomiting lasts more than a few hours, diarrhea and signs of dehydration are present, there is a fever higher than 100 °F (38 °C), or if the child hasn't urinated for six hours. For children over age six, vomiting lasts more than 24 hours, diarrhea combined with vomiting lasts for more than 24 hours, there are signs of dehydration, there is a fever higher than 102 °F (39 °C) or the child hasn't urinated for six hours. You see blood in the vomit (bright red or "coffee grounds" in appearance). You have severe headaches or a stiff neck. You experience lethargy, confusion, or a decreased alertness. You experience severe abdominal pain. You count a fever over 101 °F (38 °C). You measure rapid breathing or pulse. Bulimia is the urge to vomit after eating in order to control weight. People with Bulimia eat large amounts of food in a short time (binge) and then find a way to get rid of the food (purge). Bulimia is treated with psychological counseling, but is curable. 

Now, please write a short abstract for it in Chinese. Abstract:
要知道，大部分呕吐是正常的，但有些则代表了重大的医学问题。 如果你的情况如下，咨询医生或护士: 如果你的情况如下，马上寻找医学治疗: 如果你觉得自己可能饮食失调，如暴食症，咨询专家。