Causes can be:

- Mallory-Weiss syndrome: bleeding tears in the esophagal mucosa, usually caused by prolonged and vigorous retching.

- Irritation or erosion of the lining of the esophagus or stomach

- Vomiting of ingested blood after hemorrhage in the oral cavity, nose or throat

- Vascular malfunctions of the gastrointestinal tract, such as bleeding gastric varices or intestinal varices

- Tumors of the stomach or esophagus.

- Radiation poisoning

- Viral hemorrhagic fevers

- Gastroenteritis

- Gastritis

- Peptic ulcer

- Chronic viral hepatitis

- Intestinal schistosomiasis (caused by the parasite "Schistosoma mansoni")

- History of smoking

- Iatrogenic injury (invasive procedure such as endoscopy or transesophageal echocardiography)

- Zollinger–Ellison syndrome (severe peptic ulcer)

- Atrio-oesophageal fistula

- Yellow fever

Hematemesis is treated as a medical emergency. The most vital distinction is whether there is blood loss sufficient to cause shock.

Embryonal carcinoma is a relatively uncommon type of germ cell tumour that occurs in the ovaries and testes.

In the ovary, embryonal carcinoma is quite rare, amounting to approximately three percent of ovarian germ cell tumours. The median age at diagnosis is 15 years. Symptoms and signs are varied, and may include sexual precocity and abnormal (increased, reduced or absent) uterine bleeding.

There may be elevations in serum human chorionic gonadotropin (hCG) and alpha fetoprotein (AFP) levels but it would be in association with other tumors, (e.g. yolk sac tumor) because they themselves do not produce the serum markers. At surgery, there is extension of the tumour beyond the ovary in forty percent of cases. They are generally large, unilateral tumours, with a median diameter of 17 centimetres. Long-term survival has improved following the advent of chemotherapy. The gross and histologic features of this tumour are similar to that seen in the testis.