Uncommon Causes Of Hypertension

While 90-95 percent of patients having high blood pressures 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, a lack of exercise and obesity. Whereas, secondary hypertension may be caused by a number of uncommon causes or diseases. Following are some of the not so common yet important and treatable causes of hypertension.

1) Kidney Diseases:

Several kidney diseases may cause secondary hypertension, including 

• Diabetic nephropathy. Can damage the kidneys' filtering system, and lead to high blood pressure. 
• Polycystic kidney disease. An inherited condition marked by multiple cysts in the kidney
• Glomerulonephritis and Nephrotic syndrome. 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.

2) Endocrine Diseases:

Medical conditions affecting body hormone levels may also cause hypertension. These conditions may include:

• Cushing syndrome. Caused by a pituitary tumour that causes the adrenal glands to produce too much of the hormone cortisol.
• Aldosteronism. In this condition, a tumour in one or both of the adrenal glands increased hormone aldosterone. This makes kidneys to retain salt and water which raises blood pressure.
• Pheochromocytoma. Tumour of the adrenal gland which increases the production of the hormones adrenaline and noradrenaline.
• Thyroid problems. When the thyroid gland produces too much thyroid hormone (hyperthyroidism), high blood pressure can result. Hypothyroidism can also lead to high blood pressures.
• Hyperparathyroidism. Levels of calcium and phosphorus are altered which may lead to hypertension.

3) Coarctation of the aorta:

Usually congenital but may not be detected until adulthood because it is often asymptomatic.5. 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.

4) Sleep apnea. Common in middle-aged obese males and is marked by severe snoring. 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 number of stress hormones, which can also raise blood pressure. 

5) Obesity:

Obesity causes an increase in the total circulating volume of the body thereby increasing the blood pressure.
 Also, fat deposits can release chemicals that raise blood pressure.

6) Sugar: 

High sugar levels increase the blood insulin levels, which spurs the sympathetic nervous system and results in increased blood pressure.

7) Pregnancy:

Pregnancy can make existing high blood pressure worse or may cause high blood pressure to develop (pregnancy-induced hypertension or preeclampsia).

8) 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, liquorice and ephedra, may cause high blood pressures. A 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. 

Dr Udgeath Dhir

Guest Author Dr Dhir is Director and Head Cardiac Surgery Fortis Memorial Research Institute. He has operated around 7500 cases in the tenure of eleven years. He is formally trained by Dr. Taweseeak for Rheumatic Mitral valve repair at Central Chest Institute, Bangkok and recently got trained for TAVI. He has been associated with Escorts Heart Institute & Research Centre, New Delhi. His last association was with Medanta - The Medicity, Gurgaon as Senior Consultant- CTVS.