Upper gastrointestinal bleeding may lead to vomiting of blood, black stools and blood in the stool, palpitations, dizziness and fainting. Vomiting blood, black stools and blood in stools: The clinical manifestations of upper gastrointestinal bleeding depend on the rate and amount of bleeding and how long the blood stays in the digestive tract. Vomiting blood or black stool is a characteristic manifestation of upper gastrointestinal bleeding. Vomiting blood is accompanied by black stools, whereas black stools are not necessarily accompanied by vomiting blood. When bleeding is heavy and rapid, the blood stays in the stomach for a shorter period of time, and the vomited blood tends to be bright red in color. When the blood remains in the stomach for a long time, it tends to be brownish coffee-like after the action of stomach acid. As the blood stays longer in the intestines, the hemoglobin in the blood and the sulfide in the intestines form iron sulfide under the action of bacteria, which is mainly manifested as black stools, also known as tarry stools. 2. Palpitation, dizziness, fainting: because vomiting blood will cause the circulating blood volume to decrease, which will lead to dizziness, palpitation, fainting and even coma and other symptoms. If symptoms of upper gastrointestinal bleeding occur, it is recommended to consult a doctor in time for targeted treatment under the guidance of the doctor.