Bright red streaks of blood in the vomit can be caused by irritation of the mouth or nose from vomiting. This is not serious if there is only a small streak of blood that you are quite sure came from your mouth or nose.

A moderate to large amount of blood in vomit indicates bleeding in the digestive tract (gastrointestinal tract [GI tract]), usually from the esophagus, stomach, or upper part of the small intestine (duodenum). Digestive tract bleeding can be caused by inflammation, peptic ulcer disease, gastritis, or tears in the esophagus. If bleeding is severe, the vomit will be mostly blood or material that looks like coffee grounds (partially digested blood).

Call your doctor right away if you have more than a small streak of blood in your vomit or if you are not sure the blood came from your mouth or nose.