What causes hematemesis?

Hematemesis (vomiting blood) has numerous potential causes—over ten distinct diseases may lead to this symptom. Generally, hematemesis always indicates an underlying pathological condition. If the vomited blood appears bright red or pinkish and frothy, it typically originates from the respiratory tract—for example, pulmonary tuberculosis, bronchiectasis, or acute left-sided heart failure.

Conversely, if the vomited blood is coffee-ground in appearance, black, or dark red, it usually signifies upper gastrointestinal bleeding. The most common cause of upper GI bleeding is peptic ulcer disease—including gastric ulcers and duodenal ulcers. When an ulcer erodes into a blood vessel, hematemesis may occur; if it ruptures into an artery, bleeding can be massive and life-threatening, necessitating immediate medical attention.

A second major cause of hematemesis is rupture of esophageal or gastric varices, commonly seen in patients with liver cirrhosis and portal hypertension. Such patients often have a history of hepatitis or cirrhosis and are usually able to recognize the severity of hematemesis, prompting prompt medical consultation. Without timely treatment, this condition can also be life-threatening.

A third cause is Mallory-Weiss syndrome—acute mucosal laceration at the gastroesophageal junction, typically triggered by severe vomiting (e.g., after excessive alcohol consumption or repeated induced vomiting). This results in the vomiting of fresh blood and requires urgent medical evaluation and hemostatic therapy. A fourth cause includes gastric malignancies, such as gastric cancer, which may also present with hematemesis and warrants immediate hospital referral. Regardless of the underlying cause, any episode of hematemesis signals an underlying disease and necessitates prompt medical evaluation.