High blood pressure (hypertension) is a serious medical condition characterized by repeated high blood pressure readings. One high reading doesn't mean someone has hypertension, but several high readings over time can indicate a problem. Several lifestyle factors, medical conditions and drugs can contribute to the development of this condition.
Kidney Disorders
High blood pressure is the second leading cause of kidney disease. However, kidney disorders can also cause high blood pressure. Kidney functions include removing wastes from the body, balancing fluid and electrolytes and controlling blood pressure. Blood pressure is controlled with an enzyme produced by the kidneys. This enzyme is known as renin, and its production is often increased in cases of kidney disease and other kidney disorders. When there is too much renin, blood pressure increases.
Adrenal Tumors
Hormones produced by the adrenal gland affect blood pressure levels, heart rate and the body's responses to stress and fear. Norepinephrine, a hormone produced by the adrenal glands, has a strong impact on blood pressure. Adrenal tumors that grow large enough to increase production of norepinephrine can cause high blood pressure. An example of an adrenal tumor is the pheochromocytoma. The Mayo Clinic defines a pheochromocytoma as an adrenal tumor that affects the core of the adrenal gland. These tumors are usually benign, but they can cause increased blood pressure and heart rate.
Drugs
Several prescription drugs are known to cause increased blood pressure levels. Hormonal birth control pills--particularly those containing estrogen--are known to cause high blood pressure. Decongestants, which act to reduce the feeling of a stuffy nose, can cause noticeable increases in blood pressure. The American Heart Association recommends that anyone with high blood pressure avoid cold and flu products that contain oxymetazoline, propylhexedrine, pseudoephedrine, ephedrine, levmetamfetamine, phenylephrine, synephrine, naphazoline, phenylpropanolamine and tetrahydrozoline.
Heart & Blood Vessel Defects
Heart and blood vessel defects can cause high blood pressure, particularly in infants and children who don't have other risk factors for the condition. When a heart or blood vessel defect is present, the heart has to work much harder to pump blood to all of the body's organs. This extra force on the arteries increases blood pressure. Examples of heart and vascular disorders that lead to high blood pressure include renal artery stenosis, coarctation of the aorta, renal vein thrombosis and aortic thrombosis.
Lifestyle Factors
Lifestyle factors play an important role in the development of hypertension. Diet, exercise, alcohol use, caffeine intake and tobacco use can also determine if someone will have high blood pressure. When someone eats foods that contain high levels of sodium, water is retained in the blood vessels. This increases blood volume, which forces the heart to pump harder. Failing to get regular exercise makes the heart muscle weaken, which means that it has to work harder to pump the same amount of blood. This extra work increases blood pressure levels. Caffeine, alcohol and tobacco use can cause increases in blood pressure, and should be avoided by anyone who has been diagnosed with hypertension.
