Dark vomit signals a medical concern and requires immediate attention from a healthcare professional. This discoloration often suggests the presence of altered blood in the stomach, indicating bleeding in the upper gastrointestinal (GI) tract. The upper GI tract includes the esophagus, stomach, and the duodenum (the first part of the small intestine). Although the cause is not always severe, the potential for serious internal issues warrants a rapid medical evaluation.
Interpreting the Shade and Texture
The dark color and characteristic texture of the vomit provide important clues about the source of the issue. Vomit that is black or very dark brown and has a granular, gritty appearance is often referred to as “coffee ground emesis.” This appearance indicates that blood has been in the stomach long enough to react with stomach acid.
The iron component within the hemoglobin oxidizes upon exposure to the stomach’s hydrochloric acid, converting the bright red hemoglobin into a dark brown or black pigment called hematin. This resulting appearance suggests a bleed that is either slow or has temporarily stopped, allowing the blood to partially digest. Bright red vomit, in contrast, suggests active, fresh bleeding that has not had time to undergo this chemical change. The consistency, whether watery, clotted, or gritty, further helps medical professionals determine the origin and severity of the bleeding.
Dietary and Medication-Related Causes
Not all instances of dark vomit are caused by internal bleeding; sometimes, the color is a harmless reflection of recent consumption. Certain foods and beverages contain naturally dark pigments that can mimic the appearance of blood after being partially digested. These items include dark-colored berries, black licorice, and dark chocolate.
Some over-the-counter medications and supplements can also cause the vomit to appear dark or black. Iron supplements are a common culprit, as the iron can oxidize and darken stomach contents. Bismuth subsalicylate compounds, used to treat upset stomachs and diarrhea, can also cause temporary discoloration of the tongue, stool, and vomit. While these causes are generally not concerning, a medical evaluation is still necessary to definitively rule out a serious pathological condition.
Pathological Causes of Dark Vomit
When dark vomit is pathological, it is usually a manifestation of upper gastrointestinal bleeding, a condition that requires urgent medical investigation. The most frequent cause is a peptic ulcer, an open sore that develops on the lining of the stomach or duodenum. These ulcers can erode a blood vessel, leading to bleeding that mixes with stomach acid and causes the coffee-ground appearance.
Another cause is gastritis, the inflammation and irritation of the stomach lining; severe cases can result in bleeding. Mallory-Weiss tears are lacerations in the mucous membrane of the lower esophagus or upper stomach, often caused by forceful or repeated vomiting and retching. These tears can cause significant bleeding.
Conditions like esophageal varices involve abnormally enlarged veins in the lower part of the esophagus, usually occurring in people with severe liver disease. When these fragile veins rupture, they can cause profuse bleeding, which, if not immediately expelled, can also turn dark. Less common but serious causes include certain cancers of the stomach or esophagus, where a tumor erodes into a blood vessel.
When Emergency Medical Care Is Necessary
Because dark vomit often signifies internal bleeding, seeking immediate medical attention is necessary to prevent complications. Prompt action is particularly important if the dark vomit is accompanied by other signs of significant blood loss or shock.
These signs include feeling dizzy or lightheaded, especially when standing, or fainting. A rapid heart rate, pale or clammy skin, and confusion indicate that the body is struggling with a sudden loss of blood volume. If the volume of dark vomit is large or if the vomiting is continuous, emergency services should be contacted immediately. Providing medical professionals with specific details about the color, texture, and approximate volume of the vomit, along with any associated symptoms, helps expedite the diagnostic process.