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In malignant hypertensive nephrosclerosis, severe high blood pressure (malignant hypertension) damages the smallest arteries in the kidneys, and kidney failure progresses rapidly.
Malignant hypertensive nephrosclerosis occurs in about 1 out of 200 people with high blood pressure and is more common among blacks than whites. It is most common in men during their 40s and 50s and women during their 30s.
High blood pressure (hypertension) causes damage to body organs. However, usually the damage takes months or years to develop. In malignant hypertension, organ damage develops over hours or days. Because hypertension causes damage so rapidly, it is described as malignant, but in this case, malignant does not mean cancerous. Malignant hypertension most commonly results from poorly controlled high blood pressure. It may also result from other conditions, such as glomerulonephritis, chronic kidney failure, narrowing of the renal artery causing renovascular hypertension, inflammation of renal blood vessels (vasculitis), or, rarely, hormonal disorders such as pheochromocytoma, primary aldosteronism, or Cushing's syndrome.
Symptoms
Symptoms initially are caused by the effects of the severe high blood pressure on the brain, eye, and heart. Some symptoms, which may include restlessness, blurred vision, headache, nausea, vomiting, sleepiness, and confusion, result from swelling of brain and eye tissue. Seizures and coma may also occur if swelling is severe or if there is bleeding within the brain. Heart failure may cause difficulty breathing. Damage to the kidneys eventually causes the symptoms of kidney failure, such as fatigue, weakness, and itching.
Diagnosis
Malignant hypertensive nephrosclerosis is likely in people who have malignant hypertension and symptoms of kidney failure or laboratory evidence of kidney failure. By viewing the back of the eye with an ophthalmoscope, doctors can see areas of bleeding, collections of fluid, and swelling of the optic nerve. Doctors may also detect heart enlargement and heart strain or failure. These findings in the eye and heart indicate malignant hypertension.
Blood tests show elevated levels of creatinine and urea nitrogen, indicating kidney failure. Protein leaking from the kidneys can be detected in the urine, along with blood cells. Anemia often results from the breakdown and impaired production of red blood cells. Widespread clotting within the blood vessels is also common (disseminated intravascular coagulation—see Bleeding and Clotting Disorders: Disseminated Intravascular Coagulation (DIC)). Blood levels of substances produced by the kidneys that help regulate blood pressure (renin and aldosterone) are extremely high.
Prognosis
If malignant nephrosclerosis is not treated, 40 to 80% of people die within one year. However, with the best medical care, including rigorous control of high blood pressure with diet and drugs and treatment of the kidney failure, average survival can be up to 12 years. People who have less severe kidney failure improve the most with treatment.
Treatment
Treatment includes aggressive lowering of blood pressure with drugs. Lifestyle changes (for example, diet and exercise) also help lower blood pressure but rarely enough without drugs. Treating the kidney failure is also essential. Occasionally, people improve enough that dialysis can be stopped.
Last full review/revision December 2007 by Seyed-Ali Sadjadi, MD
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