Vomiting blood is a medical emergency and requires immediate medical assistance. Go to your GP surgery or your nearest accident and emergency (A&E) department.
It can be a sign of a serious medical problem and needs to be investigated straight away.
If you vomit blood it means there's bleeding somewhere in your gullet, stomach or the first part of your small intestine (duodenum).
Haematemesis is the medical name for blood in the vomit. The amount and colour of blood can vary. For example:
you may have vomited large amounts of bright red blood
there may be streaks of blood in your vomit, mixed up with food
there may be what look like coffee grounds in your vomit, which means the blood has been in your stomach for a few hours
Keep a small sample of the vomit to show your GP or the doctor treating you. It will give them much better idea of what's wrong.
Unless you're perfectly well and the cause is obvious to your GP or doctor (for example, swallowing blood from a nosebleed), you should be admitted to hospital straight away for tests.
These will include blood tests and an endoscopy. This is where a thin, flexible tube with a light and camera at one end (an endoscope) is used to examine the inside of your digestive tract.
It's important to confirm that the blood you've vomited has come from your stomach or gullet, and that you haven't coughed it up from your airways or lungs, which would indicate a completely different problem. Read about coughing up blood.
Below is a summary of the most likely causes of blood in the vomit. It's a rough guide that should give you a better idea of the problem. However, don't use it to diagnose yourself – always leave that to your GP or doctor.
Common causes of vomiting blood
The most common causes of vomiting blood are discussed below.
Stomach ulcer or severe gastritis
A stomach ulcer or severe gastritis (stomach lining inflammation) are the most likely cause of vomiting blood if you also have a burning or gnawing pain in your tummy.
Bleeding occurs when the ulcer or inflammation damages an underlying artery.
Oesophageal varices are enlarged veins in the walls of the lower part of the oesophagus (gullet) that bleed but don't usually cause any pain.
They're often caused by alcoholic liver disease. If your GP or doctor suspects that oesophageal varices are the cause of blood in your vomit, you'll need to be admitted to hospital immediately.
Severe gastro-oesophageal reflux disease
Gastro-oesophageal reflux disease (GORD) is where acid leaks out of the stomach and up into the oesophagus.
If you have severe GORD it can irritate the lining of your oesophagus and cause bleeding.
Tear in the oesophagus
Prolonged retching can tear the lining of your oesophagus, which can also result in bleeding.
It's possible to swallow blood in certain circumstances – for example, after a severe nosebleed.
The above conditions may also cause you to have blood in your stools (causing black, tarry poo).
Less common causes of vomiting blood
Less commonly, blood in your vomit may be caused by:
swallowing poisons – such as corrosive acid or arsenic
a blood condition – such as thrombocytopenia (a reduced number of platelets in the blood), leukaemia, haemophilia or anaemia
cancer of the oesophagus or stomach cancer – cancer may be suspected if you're over 55 and you've also lost a lot of weight (it's otherwise rare)
Haematemesis is the medical name for blood in the vomit