Hematemesis is the vomiting of blood. It is always an important sign. It can be confused with hemoptysis (coughing up blood) or epistaxis (nosebleed), which are more common. The source is generally the upper gastrointestinal tract, typically above the suspensory muscle of duodenum. It may be caused by ulcers, tumors of the stomach or esophagus, varices, prolonged and vigorous retching, gastroenteritis, ingested blood (from bleeding in the mouth, nose, or throat), or certain drugs.Hematemesis is treated as a medical emergency, with treatments based on the amount of blood loss. Investigations include endoscopy. Any blood loss may be corrected with intravenous fluids and blood transfusions. Patients may need to avoid taking anything by mouth. Definition
Hematemesis is the vomiting of blood. This is usually vomit that contains bright red blood. Coffee ground vomiting is similar to hematemesis, but is distinct in not involving bright red blood.Hematemesis is always an important sign. It must be differentiated from hemoptysis (coughing up blood) and epistaxis (nosebleed). Both of these are more common conditions. These may be difficult to distinguish. Differential diagnosis
Hematemesis may be caused by:

Peptic ulcer. This may be related to Zollinger–Ellison syndrome, which causes severe disease. Vascular malfunctions of the gastrointestinal tract, such as bleeding gastric varices or intestinal varices. Mallory-Weiss syndrome: bleeding tears in the esophagal mucosa, usually caused by prolonged and vigorous retching. Vomiting of ingested blood after bleeding in the mouth, nose, or throat. Tumors of the stomach or esophagus. Irritation or erosion of the lining of the esophagus or stomach. Radiation poisoning. Viral hemorrhagic fevers.
Pseudofolliculitis barbae (PFB) is a persistent irritation caused by shaving. It was first described in 1956. Signs and symptoms
Related conditions
Razor burn is a less serious condition caused by shaving, characterized by mild to moderate redness and irritation on the surface of the skin. Unlike PFB, it is usually transient and there is no infection involved. There is also a condition called folliculitis barbae. The difference between the two is the cause of the inflammation in the hair follicles. Where folliculitis barbae is caused by viral or bacterial infections, pseudofolliculitis is created by irritation from shaving and ingrown hairs. Pseudofolliculitis nuchae, a related condition, occurs on the back of the neck, often along the posterior hairline, when curved hairs are cut short and allowed to grow back into the skin. Left untreated, this can develop into acne keloidalis nuchae, a condition in which hard, dark keloid-like bumps form on the neck. Both occur frequently in black men in the military. Here it is so common that services often have known protocols for management. Cause
Pseudofolliculitis barbae (PFB) is most common on the face, but it can also happen on other parts of the body where hair is shaved or plucked, especially areas where hair is curly and the skin is sensitive, such as genital shaving (more properly termed pseudofolliculitis pubis or PFP).After a hair has been shaved, it begins to grow back. Curly hair tends to curl into the skin instead of straight out of the follicle, leading to an inflammation reaction.