Vomiting blood is a backward flowing (regurgitation) of blood through the upper gastrointestinal (GI) tract. The upper GI tract includes the stomach, mouth, throat, esophagus (the swallowing tube), and the first part of the small intestine.

Vomiting blood results from upper gastrointestinal bleeding. It can sometimes be difficult to tell the difference between vomiting blood and coughing up blood (from the lung) or a nosebleed.

Conditions that cause vomiting blood can also cause blood in the stool.

There are several reasons why someone may vomit blood. For example, vomiting that is very forceful or continues for a very long time may cause a tear in the small blood vessels of the throat or the esophagus, producing streaks of blood in the vomit.

Other causes may include:

• Bleeding ulcer in the stomach, first part of the small intestine, or esophagus
• Bleeding esophageal varices or stomach varices
• Defects in the blood vessels of the GI tract
• Infection of the stomach and intestines (gastroenteritis)
• Inflammation of the esophagus lining (esophagitis)
• Inflammation of the stomach lining (gastritis)
• Irritation or erosion of the lining of the esophagus or stomach
• Swallowing blood (for example, swallowed after a nosebleed)
• Tumors of the stomach or esophagus