Malignant hypertension is extremely high blood pressure that develops rapidly and causes some type of organ damage. Normal blood pressure is below 120/80. A person with malignant hypertension has a blood pressure that’s typically above 180/120. Malignant hypertension should be treated as a medical emergency.
In many people, high blood pressure is the main cause of malignant hypertension. Missing doses of blood pressure medications can also cause it. In addition, there are certain medical conditions that can cause it. They include:
Malignant hypertension is rare. About 1% of people who have a history of high blood pressure develop this life-threatening condition.
You are at greater risk of developing it if you are a man, or someone of lower economic status. Poor access to health care increases the risk.
The main symptoms of malignant hypertension are a rapidly increasing blood pressure of 180/120 or higher and signs of organ damage. Usually, the damage happens to the kidneys or the eyes.
Other symptoms depend on how the rise in blood pressure affects your organs. A common symptom is bleeding and swelling in the tiny blood vessels in the retina. The retina is the layer of nerves that line the back of the eye. It senses light and sends signals to the brain through the optic nerve, which can also be affected by malignant hypertension. When the eye is involved, malignant hypertension can cause changes in vision.
Other symptoms of malignant hypertension include:
In rare cases, malignant hypertension can cause brain swelling, which leads to a dangerous condition called hypertensive encephalopathy. Symptoms include:
High blood pressure, in general, makes it difficult for kidneys to filter wastes and toxins from the blood. It is a leading cause of kidney failure. Malignant hypertension can cause your kidneys to suddenly stop working properly.
A diagnosis of malignant hypertension is based on blood pressure readings and signs of acute organ damage.
If you have symptoms of malignant hypertension, the doctor will:
Additional blood tests may be needed, depending on the result of the tests listed above.
The doctor will also ask for imaging tests, including:
Malignant hypertension is a medical emergency and needs to be treated in a hospital, often in an intensive care unit. The doctor will consider your symptoms and overall health when deciding what treatment plan is best for you. The goal of treatment is to carefully lower your blood pressure within a matter of minutes.
You will receive blood pressure medicines through an IV, which is the quickest way to treat extremely high blood pressure. Once blood pressure is at a safe level, the medications may be switched to oral forms. If you develop kidney failure, you may need kidney dialysis.
Other treatments depend on your specific symptoms and possible causes of the malignant hypertension.
Untreated, malignant hypertension causes death. Complications of malignant hypertension also may include:
Immediate medical treatment decreases your chances for life-threatening complications.
In about 10% of people, high blood pressure is caused by another disease. If that is the case, it is called secondary hypertension. In such cases, when the root cause is treated, blood pressure usually returns to normal or is significantly lowered. These causes include the following conditions:
In the other 90% of cases, the cause of high blood pressure is not known (primary hypertension). Although the specific cause is unknown, certain factors are recognized as contributing to high blood pressure.
Renal hypertension, also called renovascular hypertension, is elevated blood pressure caused by kidney disease. It can usually be controlled by blood pressure drugs. Some people with renal hypertension can be helped by angioplasty, stenting, or surgery on the blood vessels of the kidney.
Renal hypertension is caused by a narrowing in the arteries that deliver blood to the kidney. One or both kidneys’ arteries may be narrowed. This is a condition called renal artery stenosis.
When the kidneys receive low blood flow, they act as if the low flow is due to dehydration. So they respond by releasing hormones that stimulate the body to retain sodium and water. Blood vessels fill with additional fluid, and blood pressure goes up.
The narrowing in one or both renal arteries is most often caused by atherosclerosis, or hardening of the arteries. This is the same process that leads to many heart attacks and strokes. A less common cause of the narrowing is fibromuscular dysplasia. This is a condition in which the structure of the renal arteries develops abnormally for unclear reasons.
Renal hypertension usually causes no symptoms. The narrowing in the arteries can’t be felt. Unless it’s dangerously high, high blood pressure causes no symptoms, either. Symptoms of severely elevated blood pressure include:
The vast majority of people with renal hypertension never experience these (or any) symptoms. High blood pressure is dangerous, partly because there are no symptoms, so organ damage can occur slowly without being recognized.
Renal hypertension can cause chronic kidney disease. This is a slow decline in kidney function. Until the condition is well advanced, chronic kidney disease also causes no symptoms.
Because there are usually no symptoms, a doctor may suspect renal hypertension when someone has uncontrolled high blood pressure despite multiple medications or has unexplained chronic kidney disease.
Medications are used first to try to control high blood pressure in renal hypertension. The most important blood pressure medications to treat renal hypertension include:
For most people with renal hypertension due to renal artery narrowing, medications can effectively control blood pressure. More than one blood pressure drug is often needed, however.
In some people with renal hypertension due to narrowing of the renal artery, even taking three or more medications every day may not adequately control blood pressure. In these situations, a procedure to improve blood flow to the kidneys may help.
Possible procedures include:
Angioplasty. A doctor threads a catheter through a large artery in the groin and advances it into the renal artery. A balloon is then inflated for a few moments. This widens the artery and improves blood flow.
Stenting. During angioplasty, a wire-mesh stent can be expanded inside the renal artery. The stent stays in place. This keeps the artery open after the balloon is removed. Research, however, has not shown that stenting is more effective than medication for renal hypertension.
Surgery. A surgeon can bypass the narrowed renal artery by sewing a healthy blood vessel next to it. Surgery is generally considered only when angioplasty and stenting are not possible.
These procedures are similar to those used to improve blood flow in the heart in people with coronary artery disease.
Results of Treatment
For people whose blood pressure is not controlled with multiple medications or for those who can’t tolerate blood pressure medication, surgery may be an effective fix for renal hypertension.
If a procedure is needed, renal artery stenosis is almost always treated by stenting or angioplasty. However, stenting/angioplasty has not been shown to be beneficial in most studies compared to medical management alone. Still, it may have a role for treatment in some people. Generally, procedures are more effective when only one kidney’s artery is narrowed rather than both.