Causes of Hypertension

A number of medical conditions can cause secondary hypertension. These include:
•    Diabetes complications (diabetic nephropathy). Your kidneys contain millions of tiny blood vessels that filter waste from your blood and get rid of it through your urine. But diabetes can damage this filtering system. In fact, diabetic nephropathy is the most common type of kidney failure — which is nearly always associated with high blood pressure. The high blood pressure can be treated with diet, exercise and medication.
•    Polycystic kidney disease. In this inherited condition, cysts in your kidneys prevent them from working normally, and can raise blood pressure. The high blood pressure can be treated with diet, exercise and medication.
•    Glomerular disease. Your kidneys filter waste and sodium using microscopic filters called gloomier. Swelling of these filters is called glomerulonephritis. If the swollen glomeruli can't work normally, you may develop high blood pressure. The high blood pressure can be treated with diet, exercise and medication. Glomerulonephritis may be treated with medication, and if needed, with dialysis or a kidney transplant.
•    Hydronephrosis. In this condition, certain parts of one or both kidneys become plugged due to kidney stones, a tumor or other reasons. This blocks urine flow and raises blood pressure. Some blockages resolve without treatment, but others require drainage or surgery. Once the blockage is removed, blood pressure often returns to normal.
•    Renovascular hypertension. This is a type of secondary hypertension caused by narrowing (stenosis) of one or both arteries leading to your kidneys. Nonvascular hypertension can cause severe hypertension and irreversible kidney damage. It's often caused by the same type of fatty plaques that can damage your coronary arteries (arteriosclerosis) or a condition in which the muscle and fibrous tissues of the renal artery wall thicken and harden into rings (fibromuscular dysplasia).
In mild cases, the high blood pressure may be treated with diet, exercise and medication while kidney function is simply monitored. In more severe cases, the doctor may open clogged arteries with a procedure known as angioplasty. Wire mesh tubes (stents) may be used to hold the arteries open. Another option is to surgically bypass blood flow around the affected arteries. Once blood flow to the kidneys improves, blood pressure usually returns to normal.
•    Cushing's syndrome. In this condition, corticosteroid medications, a pituitary tumor or other factors cause the adrenal glands to produce too much of the hormone cortisone. This raises blood pressure. Treatment may include surgery, radiation therapy or medication to return both cortisol and blood pressure to normal.
•    Aldosteronism. In this condition, a tumor in the adrenal gland, increased growth of normal cells in the adrenal gland or other factors cause the adrenal glands to release an excessive amount of the hormone aldosterone. This makes your kidneys retain salt and water and lose too much potassium, which raises blood pressure. Treatment may include medication to block the action of aldosterone, surgery to remove a tumor in the adrenal gland, and diet, exercise and medication to treat the high blood pressure.
•    Pheochromocytoma. This rare tumor in the adrenal gland increases production of the hormones adrenaline and noradrenaline, which can lead to long-term high blood pressure or short-term spikes in blood pressure. Surgery to remove the tumor usually returns your blood pressure to normal.
•    Hypothyroidism. This condition occurs when the thyroid gland doesn't produce enough thyroid hormone, which can cause high blood pressure. Hypothyroidism may have various causes, including inflammation, surgery, radiation treatment, certain medications or pituitary problems. Treatment with synthetic thyroid hormones usually returns blood pressure to normal.
•    Hyperthyroidism. This condition occurs when the thyroid gland produces too much thyroid hormone. This can increase the activity of epinephrine and norepinephrine, which can increase blood pressure. Treatment may include medication, radioactive iodine therapy or surgery, all of which can restore normal blood pressure.
•    Hyperparathyroidism. The parathyroid glands regulate levels of calcium and phosphorus in your body. If the glands secrete too much parathyroid hormone, the amount of calcium in your blood rises — which triggers a rise in blood pressure. Treatment is typically removal of the parathyroid glands, which returns blood pressure to normal.
•    Coarctation of the aorta. With this defect you're born with, the body's main artery (aorta) is narrowed (coarctation). This forces the heart to pump harder to get blood through the aorta and to the rest of your body. This, in turn, raises blood pressure — particularly in your arms. Surgery to repair the aorta can restore normal blood pressure.
•    Sleep apnea. In this condition, often marked by severe snoring, breathing repeatedly stops and starts during sleep, meaning you don't get enough oxygen. Not getting enough oxygen may damage the lining of the blood vessel walls, which may make your blood vessels less effective in regulating your blood pressure. Treating sleep apnea with a pressure mask, devices you wear on your nose, surgery, weight loss or other steps can help control the high blood pressure.
•    Obesity. As you gain weight, the amount of blood circulating through your body increases. This puts added pressure on your artery walls, increasing your blood pressure. In addition, excess weight often is associated with an increase in heart rate and a reduction in the capacity of your blood vessels to transport blood. All of these factors can increase blood pressure.
•    Preeclampsia. This pregnancy complication, characterized by protein in the urine and elevated blood pressure, can develop after the 20th week of pregnancy. Left untreated, preeclampsia can lead to life-threatening complications for both mother and baby. The only cure for proclaims is delivery of the baby, which restores normal blood pressure.