What blood in vomit can look like

Colour alone cannot show the amount or seriousness of bleeding. Treat suspected blood as an urgent medical problem, including when the vomit contains only dark granular material.

Bright red blood may be relatively fresh. Dark granules can form after blood has had contact with stomach acid. Blood can also be mixed through food or fluid, appear as streaks after forceful retching, or form darker clots.

Some foods, drinks, and medicines can colour vomit red or dark, but appearance is not a safe way to rule bleeding out. Vomited blood generally comes from the upper digestive tract; swallowed blood from a nose or mouth bleed can sometimes look similar. Oesophageal cancer and stomach cancer can present with vomiting blood, although many other conditions can cause this sign.

Seek urgent medical attention. If it is easy and safe, note whether the material was bright, dark, granular, streaked, or clotted and whether food was mixed in. A photograph can help the clinician, but do not postpone leaving to take one.

Report retching, nosebleeds, abdominal pain, black stools, alcohol use, liver problems, and all medicines. Blood thinners, aspirin, and anti-inflammatory pain medicines are particularly relevant; do not take extra doses while awaiting medical advice.

Any suspected blood in vomit deserves urgent assessment. Use emergency services for repeated or heavy vomiting of blood, fainting, confusion, severe weakness, shortness of breath, fast breathing, cold clammy skin, severe chest or abdominal pain, or black sticky bowel motions.

Dark coffee-ground material is still a warning sign even without bright red blood, because altered blood can have this appearance.

Ask whether the appearance fits bleeding, where the source may be, whether you need an endoscopy, and what medicine changes are appropriate. Request clear instructions for eating, drinking, follow-up, and responding if the vomit returns.