What should you know about dried blood in vomit?

Blood exposed to stomach acid can turn dark brown or black and may look like wet coffee grounds. Bleeding can arise from the oesophagus, stomach, or upper intestine. Causes include irritation, an ulcer, a tear after forceful vomiting, medicines that affect bleeding, or another digestive condition. Cancer of the oesophagus or stomach is one possible cause, but the appearance alone cannot identify the source or explain how serious it is. Swallowed blood from the mouth or nose can also change the colour of vomit.

Contact urgent medical services for advice rather than waiting to see whether it happens again. Do not take aspirin, anti-inflammatory painkillers, or alcohol unless a clinician tells you to, and do not stop a prescribed blood thinner without medical advice. Avoid eating or drinking until you have received instructions if bleeding is ongoing. Note the colour and amount, when it started, medicines you take, and whether your stools are black or tar-like. A clinician may check your circulation and blood tests and arrange further examination.

Call emergency services immediately for repeated vomiting of blood, bright-red blood, faintness, confusion, cold or clammy skin, rapid breathing, severe abdominal or chest pain, or black stools with weakness. Do not drive yourself if you feel faint. Even a small amount of dark vomit warrants prompt assessment because bleeding can continue without looking dramatic.

Where might the blood have come from? Could any of my medicines or recent vomiting have contributed? Do I need blood tests, a camera examination, or imaging? What warning signs should bring me back urgently?