When a person vomits blood, he regurgitates blood from his gastrointestinal tract. Sometimes the vomiting of blood, also called hematemesis, may occur in relation to a minor medical condition, or it may be an indication of a serious illness or disease. Among the most common causes of vomiting blood are bleeding ulcers, swallowed blood, or gastrointestinal tract tumors. Sometimes, however, a person may see blood in vomit because he has vomited so forcefully or for such an extended time that blood vessels in his esophagus or throat have torn and bled. Additionally, some people may expel blood through their mouths as a result of coughing and assume they've vomited blood.
Bleeding ulcers are among the most common conditions that cause blood in vomit. For example, a person may develop a hole, referred to as an ulcer, in part of his digestive system. If the hole eventually grows larger and begins to damage blood vessels, it may be called a bleeding ulcer. Likewise, an ulcer may grow so that it causes a hole to form in a person’s intestine or in both his intestine and an organ. Both of these conditions may cause a person to vomit blood.
Tumors of the digestive system may sometimes cause a person to vomit blood. For example, an individual may develop a tumor in the lining of his esophagus, which may cause blood to be present in his vomit. These tumors can be benign, which means not cancerous, or malignant, which means cancerous. Regardless of whether or not a tumor is cancerous, however, it may sometimes cause a patient to see blood in vomit. Likewise, a person who has a benign or malignant tumor in his stomach may also vomit blood.
In some cases, blood in vomit isn't related to a disease or condition of the digestive tract. Instead, it may occur because of something as simple as a nosebleed. When a person has a nosebleed, some of the blood may drip down his throat and into his stomach. This may cause some people to feel nauseated and vomit blood. Some people may even cough up blood for reasons unrelated to the digestive tract and assume they've vomited it up instead of coughed it up.
A person may also see blood in vomit because of injuries caused by vomiting. For example, a person who vomits violently or over an extended period of time may tear blood vessels in his throat and see blood in his vomit. Usually, the blood is present in streaks rather than in large pools. Some people may even cough up blood for reasons unrelated to the digestive tract and assume they've vomited it up instead of coughed it up.