Vomiting is often a sign of an upset stomach or an infection. Vomiting in women may be a sign of pregnancy; it can occur at any time, but it often happens in the morning. Other causes of vomiting include excessive eating, food poisoning, or medications. Excessive vomiting should be treated as an emergency because it will lead to dehydration and affect body organ functions. It also may cause poor blood circulation, resulting in light-headedness and decreased activity. Since vomiting is a symptom of various conditions, seek medical attention immediately to determine the cause and get proper treatment.