Causes High Blood Pressure (Hypertension)

When a person has hypertension caused by another medical condition, it is called secondary hypertension. Secondary hypertension can be caused by a number of different illnesses. Many people with kidney disorders have secondary hypertension. The kidneys regulate the balance of salt and water in the body. If the kidneys cannot rid the body of excess salt and water, blood pressure goes up. Kidney infections, a narrowing of the arteries that carry blood to the kidneys, called renal artery stenosis, and other kidney disorders can disturb the salt and water balance.

Cushing's syndrome and tumors of the pituitary and adrenal glands often increase levels of the adrenal gland hormones cortisol, adrenalin, and aldosterone, which can cause hypertension. Other conditions that can cause hypertension are blood vessel diseases, thyroid gland disorders, some prescribed drugs, alcoholism, and pregnancy.
Even though the cause of most hypertension is not known, some people have risk factors that give them a greater chance of getting hypertension. Many of these risk factors can be changed to lower the chance of developing hypertension or as part of a treatment program to lower blood pressure.
Certain medications including birth control pills, cold remedies, decongestants, over-the-counter pain relievers and some prescription drugs also may cause secondary hypertension. In a 2005 study, women who took an average of 500 milligrams or more of acetaminophen (Tylenol, others) daily over several years were more likely to develop high blood pressure than were women who didn't take any acetaminophen. It's not known if the same holds true for men.
Various illicit drugs, including cocaine and amphetamines, also can increase blood pressure.