Vomiting blood, medically known as haematemesis, is one of those symptoms you simply cannot ignore. It is not only unsettling to experience, but it can also be a warning sign of something serious happening inside your body. Understanding the causes of vomiting blood can help you make sense of what is going on and ensure you seek appropriate medical care. At London Urgent Care Centre, we provide rapid assessment for patients experiencing gastrointestinal bleeding, helping to identify the underlying cause and ensure you receive the right treatment without delay.
In This Article
Acute upper gastrointestinal bleeding is a significant medical emergency in the UK, with an estimated incidence of 134 cases per 100,000 people annually. According to NHS guidance on vomiting blood, blood in your vomit always requires medical assessment, as the causes range from relatively minor conditions to life-threatening emergencies. Despite advances in treatment, the hospital mortality rate for upper GI bleeding remains approximately 10%, underscoring why prompt medical attention is so important.
Understanding Vomiting Blood
Before exploring the specific causes of vomiting blood, it helps to understand what the appearance of the blood can tell you. Bright red blood typically indicates fresh, active bleeding from the oesophagus or stomach. Dark blood that resembles coffee grounds suggests the blood has been partially digested by stomach acid, indicating the bleeding may be slower or from further down the digestive tract. For a detailed explanation of what different types of bloody vomit mean, see our comprehensive guide.
True haematemesis must be distinguished from blood originating elsewhere. Swallowing blood from a severe nosebleed or mouth injury can appear in vomit but is not true haematemesis. Similarly, coughing up blood (haemoptysis) from the lungs is a different condition requiring different investigation.
Peptic Ulcers
Peptic ulcer disease is the single most common cause of vomiting blood, accounting for approximately 36% of all upper gastrointestinal bleeding cases according to UK audit data. This type of ulcers are open sores that develop on the lining of the stomach (gastric ulcers) or the first part of the small intestine (duodenal ulcers).
When an ulcer erodes into a blood vessel, it can cause bleeding that ranges from mild to severe. The two main causes of peptic ulcers are infection with Helicobacter pylori (H. pylori) bacteria and long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or aspirin. Other contributing factors include smoking, excessive alcohol consumption, and severe physiological stress from serious illness or surgery.
Symptoms often include burning stomach pain that may improve or worsen with eating, bloating, nausea, and in cases of bleeding, dark or black stools (melaena) as well as vomiting blood. Treatment typically involves acid-suppressing medication and, if H. pylori is present, a course of antibiotics to eradicate the infection.
Gastritis and Stomach Inflammation
Gastritis refers to inflammation of the stomach lining. When severe, this inflammation can erode the protective mucous layer and damage underlying blood vessels, causing bleeding. Gastritis is a common cause of vomiting blood, particularly when triggered by alcohol, medications, or infection.
Acute gastritis can develop rapidly after heavy alcohol consumption, use of NSAIDs or aspirin, severe stress, or infections. Chronic gastritis develops more gradually and may be caused by long-term H. pylori infection, autoimmune conditions, or bile reflux. For information specifically about vomiting blood related to alcohol consumption, see our detailed guide.
Symptoms of gastritis include gnawing or burning pain in the upper abdomen, nausea, vomiting, feeling full after eating small amounts, and in bleeding cases, blood in vomit or dark stools. Treatment focuses on removing the cause (such as stopping alcohol or NSAIDs) and using medication to reduce stomach acid and allow healing.
Oesophageal Tears (Mallory-Weiss Syndrome)
Mallory-Weiss syndrome refers to tears in the lining of the oesophagus where it meets the stomach, typically caused by forceful or prolonged vomiting. The tears occur due to the intense pressure generated during violent retching. This is one of the more common causes of vomiting blood, particularly following episodes of heavy drinking, severe morning sickness in pregnancy, or forceful vomiting from any cause.
The blood from Mallory-Weiss tears is typically bright red, reflecting fresh bleeding from the lower oesophagus. Most tears are relatively small and heal on their own within a few days. However, some require medical intervention to stop the bleeding, particularly if the patient is taking blood-thinning medication or has underlying clotting problems.
Oesophageal Varices and Liver Disease
Oesophageal varices are among the most dangerous causes of vomiting blood. These are swollen, fragile veins in the lower oesophagus that develop when liver scarring (cirrhosis) blocks normal blood flow, causing blood to back up into smaller vessels that are not designed to handle the increased pressure.
According to UK audit data, variceal bleeding accounts for approximately 11% of upper GI bleeding cases, and 9% of patients presenting with vomiting blood have known cirrhosis. When varices rupture, they can cause massive, life-threatening bleeding that requires emergency treatment.
Alcohol is the leading cause of liver disease in the UK, accounting for 6 out of every 10 cases. The British Liver Trust reports that up to 1 in 5 people in the UK consume alcohol at levels that could cause liver damage. Other causes of cirrhosis include viral hepatitis and non-alcoholic fatty liver disease.
Variceal bleeding requires urgent hospital treatment, often involving endoscopic banding (placing small rubber bands around the varices to stop bleeding) and medication to reduce pressure in the portal vein system. For those with known liver disease, preventing variceal bleeding through regular monitoring and prophylactic treatment is an important part of care.
Medications That Increase Bleeding Risk
Certain medications significantly increase the risk of gastrointestinal bleeding and are frequently implicated in cases of vomiting blood. UK data shows that 28% of patients presenting with upper GI bleeding were taking aspirin, and 11% were using NSAIDs.
NSAIDs and Aspirin
Non-steroidal anti-inflammatory drugs, including ibuprofen, naproxen, and diclofenac, reduce the stomach’s protective mechanisms and increase ulcer formation. Low-dose aspirin, taken by millions for cardiovascular protection, carries similar risks. The risk is particularly high when these medications are taken long-term, at high doses, or in combination with each other.
Anticoagulants and Blood Thinners
Medications such as warfarin, rivaroxaban, apixaban, and other anticoagulants do not directly cause bleeding but make any bleeding harder to stop. When combined with other risk factors such as ulcers or gastritis, these medications can turn minor bleeding into a significant event. If you take blood thinners and notice blood in your vomit, seek medical attention promptly.
Corticosteroids
Long-term use of corticosteroids, particularly when combined with NSAIDs, increases ulcer risk and can contribute to GI bleeding.
Other Important Causes
Several other conditions can cause vomiting blood, though they are less common than the causes discussed above.
Oesophageal and Gastric Cancer
Cancers of the oesophagus or stomach can erode into blood vessels, causing bleeding. Whilst cancer accounts for a smaller proportion of upper GI bleeding cases, it is an important diagnosis to exclude, particularly in older patients, those with unexplained weight loss, or individuals with persistent symptoms. Our gastroenterology specialists can arrange appropriate investigation if cancer is suspected.
Blood Disorders
Conditions affecting blood clotting, such as haemophilia, thrombocytopenia (low platelet count), or leukaemia, can make even minor irritation lead to visible bleeding. These conditions may cause bleeding from multiple sites, not just the digestive tract.
Severe Acid Reflux
Chronic, severe gastro-oesophageal reflux disease (GORD) can cause inflammation and ulceration of the oesophagus, potentially leading to bleeding. This is more common when reflux is untreated or inadequately controlled over long periods.
Swallowed Blood
Blood swallowed from a severe nosebleed, dental procedure, or mouth injury can subsequently be vomited. Whilst this is not true haematemesis, it can appear alarming. If you have had a recent nosebleed or mouth injury, mention this to your doctor, though medical assessment is still advisable to confirm the source.
Frequently Asked Questions
What is the most common cause of vomiting blood?
Peptic ulcer disease is the most common cause of vomiting blood, accounting for approximately 36% of cases. Ulcers in the stomach or duodenum can erode into blood vessels, causing bleeding that ranges from minor to severe.
Can stress cause vomiting blood?
Severe physiological stress from serious illness, major surgery, or trauma can cause stress ulcers that may bleed. Emotional stress alone does not typically cause vomiting blood directly, but it can worsen conditions like gastritis or acid reflux that may lead to bleeding.
Is a small amount of blood in vomit serious?
Any amount of blood in vomit should be assessed medically. Whilst small streaks may result from minor causes, they can also be the first sign of more significant bleeding. It is always safer to seek assessment and receive reassurance than to wait and risk complications.
How do doctors find the cause of vomiting blood?
The primary investigation is endoscopy (gastroscopy), where a thin, flexible camera is passed through the mouth to examine the oesophagus, stomach, and duodenum directly. According to NICE guidelines, patients with significant upper GI bleeding should receive endoscopy within 24 hours. Blood tests, liver function tests, and clotting studies help identify contributing factors.
When to Seek Emergency Help
Understanding the causes of vomiting blood is important, but knowing when to seek emergency help is essential. Call 999 or go directly to A&E if you are vomiting large amounts of blood or blood that looks like coffee grounds, you feel dizzy, faint, or confused, you have a rapid heartbeat or feel your heart racing, your skin is cold, clammy, or pale, you have severe abdominal pain, or you are passing black, tarry stools.
These symptoms may indicate significant blood loss requiring emergency treatment. Do not attempt to drive yourself to hospital.
For less severe symptoms where you have stopped vomiting blood and feel relatively stable, our London Urgent Care Centre can provide prompt assessment. We can arrange blood tests, assess your condition, and refer you for specialist gastroenterology investigation including endoscopy if needed. Our GP services can also help with ongoing management of conditions that increase bleeding risk.
Visit London Urgent Care Centre at Abbey Wood Hospital, Page Street, Mill Hill, London NW7 2ED. We are open 8am to 8pm Monday to Friday and 9am to 6pm at weekends. For more information, call 020 8358 7100 or book an appointment online.
Please note: This article provides general health information and is not a substitute for professional medical advice. Vomiting blood is a potentially serious symptom. If you are vomiting large amounts of blood, feel faint, or have severe pain, call 999 immediately. Do not drive yourself to hospital.