disease affecting the arterial supply to the kidneys, leading to ischaemia and resultant stimulation of the renin-*angiotensin-aldosterone axis. In the major vessels, the most common cause is atheromatous plaque disease. Other causes are fibromuscular dysplasia and *Takayasu’s disease.
Raised blood pressure in the PORTAL VEIN entering the LIVER. This results in increased pressure in the veins of the oesophagus and upper stomach and these grow in size to form varices – dilated tortuous veins. Sometimes these varices rupture, causing bleeding into the oesophagus. The raised pressure also causes ?uid to collect in the abdomen and form ASCITES. The commonest reason for portal hypertension is cirrhosis (?brosis) of the liver (see LIVER, DISEASES OF). THROMBOSIS in the portal vein may also be a cause. Treatment requires the cause to be tackled, but bleeding from ruptured vessels may be stopped by injecting a sclerosant or hardening solution into and around the veins. Sometimes a surgical shunt may be done to divert blood from the portal vein to another blood vessel.... portal hypertension
In this condition, increased resistance to the blood ?ow through the LUNGS occurs. This is usually the result of lung disease, and the consequence is an increase in pulmonary artery pressure and in the pressure in the right side of the heart and in the veins bringing blood to the heart. Chronic BRONCHITIS or EMPHYSEMA commonly constrict the small arteries in the lungs, thus causing pulmonary HYPERTENSION. (See also EISENMENGER SYNDROME.)... pulmonary hypertension
(benign intracranial hypertension, pseudotumour cerebri) a syndrome of raised pressure within the skull in the absence of a clear structural cause, such as a tumour. Although the cause is not certain, proposed mechanisms include impaired reabsorption of cerebrospinal fluid or venous outflow from the brain. The symptoms include headache, vomiting, double vision, and *papilloedema. The diagnosis is made by finding a high opening pressure at *lumbar puncture in the absence of a causative structural abnormality on brain imaging. It can improve spontaneously but drug therapy or neurosurgical treatment may be required to protect the patient’s vision.... idiopathic intracranial hypertension
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