Hypertension is one of the leading causes of mortality and morbidity around the world, and is an important risk factor for chronic disease burden in our country. While 90-95 per cent of patients having high blood pressure have no clear etiology and are classified as having primary or essential hypertension, 5-10 percent of people may have an underlying pathology or a reversible cause behind their high blood pressure (secondary hypertension).
Essential hypertension is usually linked to genetics, poor diet, lack of exercise and obesity. Whereas secondary hypertension may be caused by a number of uncommon causes or diseases.
On World Hypertension Day, which is celebrated on May 17 every year to promote awareness about hypertension, Dr Udgeath Dhir, director and head cardiac surgery, Fortis Memorial Research Institute shares some not to common yet important and treatable causes of hypertension.
Several kidney diseases may cause secondary hypertension, including:
*Diabetic nephropathy: It can damage the kidneys’ filtering system, and lead to high blood pressure.
*Polycystic kidney disease: It is an inherited condition marked by multiple cysts in the kidney.
*Glomerulonephritis and Nephrotic syndrome: The condition can lead to hypertension especially in children.
*Renovascular hypertension: Renovascular hypertension often is found in patients with coronary or peripheral atherosclerosis. Muscle and fibrous tissues of the renal artery wall thicken and damage the renal vasculature (fibromuscular dysplasia), causing irreversible kidney damage.
Medical conditions affecting body hormone levels may also cause hypertension. These conditions may include:
*Cushing syndrome: It is caused by a pituitary tumor that causes the adrenal glands to produce too much of the hormone cortisol.
*Aldosteronism: In this condition, a tumor in one or both of the adrenal glands, increases hormone aldosterone. This makes the kidneys retain salt and water which raises blood pressure.
*Pheochromocytoma: Tumor of the adrenal gland which increases production of the hormones adrenaline and noradrenaline.
*Thyroid problems: When the thyroid gland produces too much thyroid hormone (hyperthyroidism), it can result in high blood pressure. Hypothyroidism can also lead to high blood pressures.
*Hyperparathyroidism: In this condition, the levels of calcium and phosphorus are altered which may lead to hypertension.
Coarctation of the aorta
Usually congenital, it may, however, not be detected until adulthood because it is often asymptomatic. A narrowed part of aorta causes increased blood pressure in the proximal arteries. Classic signs of coarctation of the aorta include upper extremity hypertension, delayed or decreased femoral pulses and low blood pressure in the lower extremities.
Common in middle aged obese males, it is marked by severe snoring. In this condition, the breathing repeatedly stops and starts during sleep. Common symptoms include headache, fatigue, daytime somnolence, confusion, difficulty concentrating, depression, personality changes, hypertension, and cardiac arrhythmias.
It causes part of the nervous system to be overactive and release certain chemicals that increase blood pressure. Constant lack of sleep can also increase the amount of stress hormones, which can also raise blood pressure.
Obesity causes an increase in total circulating volume of the body, thereby increasing the blood pressure.
Also, fat deposits can release chemicals that raise blood pressure.
High sugar levels increase the blood insulin levels, which spurs the sympathetic nervous system and results in increased blood pressure.
Pregnancy can make existing high blood pressure worse, or may cause high blood pressure to develop (pregnancy-induced hypertension or preeclampsia).
Medications and supplements
Medications such as pain relievers, birth control pills, antidepressants, steroids, sex hormones and some anti-cancer drugs used after organ transplants can cause high blood pressure in some people.
Over-the-counter decongestants like pseudoephedrine, phenylephrine, and oxymetazoline and certain herbal supplements like ginseng, licorice and ephedra, may cause high blood pressures. Drug such as cocaine and methamphetamine, also increase blood pressure. Many studies have found that caffeine may also increase blood pressure. Caffeine causes a release of adrenaline, which raises blood pressure.