Stomach Bleeding Causes

Gastric bleeding can be acute or chronic. Acute cases can be mild or severe possibly even leading to death if immediate medical treatment is not sought. Chronic stomach bleeding is usually mild, although there may be acute exacerbations. A clinical evaluation, including a case history, assessment of the signs and symptoms, blood tests and imaging studies will help to identify the site of the bleeding will assist with isolating the cause.

Gastric (Stomach) Ulcers

A bleeding stomach (gastric) ulcer is the most common cause.

Helicobacter pylori (H.pylori infection)

The H.pylori bacteria affects the mucus coating of the stomach. The gastric acid and bacteria then damage the lining thereby causing an ulcer.


A number of drugs cause or aggravate a pre-existing stomach ulcer or result in inflammation of the gastric lining. (refer to Gastritis). Most of these drugs affect the normal resistance of the gastric lining to acid by disturbing mucus production (the mucus protects the stomach cells), increase gastric acid production or pH or affect the clotting process which will assist with ‘sealing’ any bleeds.

Some of the drugs that commonly cause or aggravate stomach bleeding includes :

  • NSAIDs, like ibuprofen and aspirin.
  • Antibiotics.
  • Anticoagulants, like heparin, warfarin.
  • Corticosteroids.
  • Selective-serotonin reputake inihibitors (SSRI’s used for depression and mood disorders)

Lifestyle Factors

A number of lifestyle factors may aggravate stomach ulcers. This includes :

  • Alcohol
  • Cigarette smoking
  • Stress


This refers to the inflammation and/or erosion of the stomach lining. There may not be any ulceration (open sores) but the persistent inflammation can lead to bleeding. Many of the causes and aggravating factors of stomach ulcers will contribute to gastritis.

Apart from an H.pylori infection which is the most common infectious cause, viral and fungal infections may also contribute to the development of gastritis. This frequently occurs in immunocompromised patients, like in cases of HIV infection. Other causes may also include various types of autoimmune diseases, like Hashimoto’s thyroiditis. The most common drug and lifestyle cause of gastritis includes NSAIDs (non-steroidal anti-inflammatory drugs) and alcohol consumption respectively.

Mallory-Weiss Tear

This is the second most common cause stomach bleeding. The tear occurs at the gastroesophageal junction (where the esophagus meets the stomach) and is a result of excessive pressure or force on the stomach as a result of :

These causes are usually persistent and extremely forceful in order for the tear to occur.

Stomach Cancer

Stomach bleeding due to a gastric stromal tumor is a common occurrence. Depending on the size of the tumor, this may vary from occult bleeding to excessive vomiting of bright red blood with no signs of other gastric contents. Other less common tumors like an angioma may also account for stomach bleeding.

Rare Causes of Stomach Bleeding

Congenital Arteriovascular Malformation

Congenital abnormalities of the artery-vein conduit for blood flow may account for stomach bleeding especially in infants and children. This may be associated with Osler-Weber-Rendu syndrome. There are other types of arteriovascular malformations (AVM), some of which is mentioned below, and may not be present from birth.

Portal Hypertensive Gastropathy

Increased blood pressure within the portal vein that drains blood from the stomach towards the liver may result in the formation of varices (distended vein) which is prone to bleeding.

Dieulafoy Lesion

Distension or bulging of the arteries which can lead to bleeding in the stomach cavity.


Post-operative bleeding is always a possibility shortly after surgery. It may be a long term risk in cases of gastric bypass surgery for medical weight loss.

Please note that any information or feedback on this website is not intended to replace a consultation with a health care professional and will not constitute a medical diagnosis. By using this website and the comment service you agree to abide by the comment terms and conditions as outlined on this page