[Up] [Definition & criteria] [Cardiovascular anatomy] [Hypertension causes] [High risk group] [Manifestations] [Complications] [Investigations] [Management principles] [Management] [Prevention] [Questions & answers] [Checking Blood pressure] [Medicines]

Causes of Hypertension

 Hypertension are of two types:

1. Essential Hypertension.

2. Secondary Hypertension.

• The majority (95%) of patients fall into category of 'Essential Hypertension.' In these patients, no underlying cause is found.

• In the minority (<5%), an underlying cause is found upon investigation.

 'Risk Factors' for Hypertension

• Smoking.

• Sedentary Life Style. (lack of Exercise)

• Alcohol intake.

• High Calorie Fatty food consumption.

• Obesity.

• Dyslipidemia. (Increased levels of Bad Cholesterols and /or decreased levels of Good Cholesterol).

• Family history of Hypertension.

• Family history of premature cardiovascular diseases like : Stroke, Heart attacks, Angina.

• Coexisting diseases like: Diabetes, Heart diseases.

• History of taking drugs like Steroids, or anti inflammatory drugs.

• Pat history of Hypertensive complications, such as: Stroke, Heart attacks or 'Transient Ischemic Attack'  (momentary loss of consciousness) 

• Previous history of urinary tract infection or renal disease.

 Causes and Incidence 

• The cause of primary (essential) hypertension is unknown.

• However, known risk factors include a familial history of the disease, race, obesity, tobacco smoking, stress, and a high-fat or high-sodium diet in genetically susceptible individuals. 

• Secondary hypertension is related to an underlying disease process such as renal parenchyma disorders, renal artery disease, endocrine and metabolic disorders, central nervous system disorders, and coarctation of the aorta.

• Million of people all over the world have hypertension, which is a major factor in strokes and cardiac and renal disease.

Disease Process  

• Hypertension is a disease of the vascular regulatory system in which the mechanisms that usually control arterial pressure within a certain (normal) range are altered. The central nervous system and renal presser system, as well as extra cellular volume, are the predominant mechanisms that control arterial pressure. Some combination of factors effects changes in one or more of these systems, ultimately leading to increased cardiac output and increased peripheral resistance. This elevates the arterial pressure, reducing cerebral perfusion and the cerebral oxygen supply, increasing the myocardial workload and oxygen consumption, and decreasing the blood flow to and oxygenation of the kidneys.