Types of Hypertension

There are two types of Hypertension-

• PRIMARY HYPERTENSION
• SECONDARY HYPERTENSION.

Hypertension in which there is no identifiable cause is known as PRIMARY or ESSENTIAL HYPERTENSION. Although the cause of primary hypertension is poorly understood, several factors contribute to the development of essential hypertension. These include:

• Obesity
• Genes for high blood pressure
• Low levels of nitric oxide (a naturally occurring substance in the body. Africans and African Americans have low levels of nitric oxide), and
• Insulin resistance (See the blog topic: DIABETES AND HYPERTENSION).

Over 90% of persons with hypertension have essential hypertension.

SECONDARY HYPERTENSION-

Hypertension clearly linked to a known cause is known as secondary hypertension.

This type of hypertension accounts for less than 10% of all cases and treatment of the identifiable cause results in return to normal blood pressure levels. The causes of secondary hypertension include:-

1. Kidney disease- is the most common cause of secondary hypertension.

2. Endocrine disorders- this refers to changes in hormonal levels in the body. Examples of endocrine disorders include hyperthyroidism and hypothyroidism (resulting from excessive or too little production of thyroid hormones respectively) and Cushing syndrome (resulting from excessive production of glucocorticoid hormones by the adrenal gland).

3. Stress

4. Chronic alcohol consumption

5. Prolonged use of certain medications such as oral contraceptive pills, steroids, non steroidal anti-inflammatory drugs (e.g. ibuprofen, diclofenac ), erythropoietin, and certain herbal drugs such as licorice. Prolonged abuse of nicotine, cocaine and amphetamines can also cause secondary hypertension.

6. Obstructive sleep apnea- is medical condition in which there are several episodes of cessation of breathing during sleep. It is caused by obstruction of the air passages.

7. Coarctation of the aorta- is a term used to describe a narrowing of the aorta. The aorta is the largest artery in the human body. It carries blood from the heart to smaller arteries that supply the entire body. Coarctation of the aorta occurs as a result of birth defects in the aortic valves and is usually diagnosed in children and adults under age 40. It is an important cause of hypertension in children.

8. Heavy coffee drinking- drinking 5 cups of coffee or more can result in secondary hypertension or worsen a pre-existing hypertensive state.

9. Pregnancy (See the blog topic:PREGNANCY AND HYPERTENSION.

10. Mood disorders e.g. depression.

11. Neurological disorders e.g. encephalitis, presence of a brain tumor.

12. Exposure to lead, cadmium and other heavy metals.

13. Hardening of the arteries/roughening of the inner lining of the arteries or thickening of arterial walls (arteriosclerosis).