Hypertension: High blood pressure. If it is in the blood vessels of the lung, it is called pulmonary hypertension. Used without any adjective, it usually it means systemic hypertension – high blood pressure in blood vessels carrying oxygenated blood to various parts of the body (arteries). High blood pressure in the blood vessels of the lungs is called pulmonary hypertension. If the pressure in the blood vessels of the portal circulation which drains blood from the intestines into the liver, it is known as portal hypertension. Portal hypertension is common in those with long standing liver disease.