Vomiting blood (haematemesis) is a medical symptom that always requires urgent evaluation.
The appearance of the blood can provide a clue to its source: bright red blood suggests active, brisk bleeding, while blood that looks like “coffee grounds” has been partially digested by stomach acid.
The top 3 causes of vomiting blood, accounting for the majority of clinical cases, are:
Peptic Ulcers: These are open sores that develop on the inside lining of the stomach (gastric ulcers) or the upper part of the small intestine (duodenal ulcers). They are often caused by long-term use of NSAIDs (like ibuprofen or aspirin) or an H. pylori bacterial infection. If an ulcer erodes into a blood vessel, it can cause significant bleeding.
Mallory-Weiss Tears: These are small tears in the lining of the mucous membrane where the oesophagus meets the stomach. They are almost always caused by forceful or prolonged vomiting, coughing, or retching (often following alcohol consumption or a bout of gastroenteritis).
Oesophagitis: Severe inflammation of the lining of the oesophagus, usually caused by chronic gastro-oesophageal reflux disease (GORD). Over time, the acid irritation can cause the lining to bleed, though this is typically less heavy than an ulcer or a tear.
While the top three are most frequent, other conditions can lead to blood in the vomit:
Gastritis: Inflammation of the stomach lining, which can lead to erosions that bleed. This is frequently triggered by alcohol, smoking, or certain medications.
Swallowed Blood: Sometimes, a severe nosebleed or bleeding from the mouth/throat can be swallowed and then vomited back up, mimicking internal gastric bleeding.
NSAIDS and Steroids: The combination or high-dose use of these medications can thin the protective lining of the stomach, leading to acute bleeding.
Oesophageal Varices: These are enlarged, swollen veins in the lining of the lower oesophagus, usually seen in people with advanced liver disease (cirrhosis). If these veins rupture, they cause massive, life-threatening bright red bleeding.
Stomach or Oesophageal Cancer: While less common as a cause of acute heavy bleeding, tumours can cause slow, chronic oozing of blood.
Dieulafoy’s Lesion: A rare condition where a large artery in the stomach wall protrudes through the lining and bleeds spontaneously.
The “look” of the blood is a vital piece of information for medical professionals:
| Appearance | Meaning |
| Bright Red | Indicates “fresh” or active, rapid bleeding from the oesophagus or stomach. |
| Coffee Grounds | Indicates the blood has sat in the stomach long enough for acid to turn the haemoglobin dark brown/black. |
| Melaena | This is not vomit, but black, tarry, foul-smelling stools, which often accompanies upper GI bleeding as the blood is digested. |
Vomiting blood is a medical emergency. You should call emergency services or go to A&E immediately, especially if you experience:
Large volumes of bright red blood.
Dizziness, fainting, or feeling lightheaded – signs of significant blood loss/low blood pressure.
Pale, cold, or clammy skin.
Rapid heart rate or shortness of breath.
Severe, “tearing” abdominal or chest pain.
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