Causes and Symptoms of Hypertension

Causes and Symptoms of Hypertension








Hypertension is a systolic blood pressure greater than 140 mm Hg and a diastolic pressure of greater than 90mm Hg based on the average of two or more accurate blood pressure measurement taken during two or more contacts with a health care provider. Hypertension is sometimes called the “silent killer” because people who have it are always symptoms free. The disease often accompanies other risk factors for atherosclerotic heart disease such as dyslipidemia (which is an abnormal blood fats levels), diabetes mellitus, obesity and metabolic syndrome. There are two types of hypertension, essential hypertension (primary elevation of blood pressure) and secondary hypertension (is where the elevation in blood pressure is caused by an underlying disease).

Causes of Hypertension

1. Increase in Renin-Angiotensin-Aldosterone-System (RAAS): increased activity of the R.A.A.S leads to expansion of extracellular fluid volume and increased systemic vascular resistance, resulting into increased solute concentration which increases blood pressure.
   
2. Increased level of chemo-receptors: whenever there’s a change in the circulation of blood due to a miss-match of Carbon (IV) Oxide and oxygen, the blood acidity increases spontaneously. The sympathetic supply to the heart, therefore, leads to an increase in heartbeat, which eventually pushes blood to the other body tissues.
   
3. Renal Artery Stenosis: this is a kidney disease that is caused by the narrowing of the renal artery. It can impede blood flow to the targeted kidney resulting into secondary hypertension, atrophy and can ultimately lead to renal failure if not treated.
   
4. Genetic factors: blood pressure tends to run in families, and children of hypertensive parents tend to have higher blood pressure than aged-matched children of people with normal blood pressure. This familial concordance of blood pressure may be explained, at least in part by shared environmental influences.
   
5. Environmental factors: some of the most significant environmental factors that have been proposed by medical experts to cause essential hypertension include but not limited to obesity, alcohol intake, too much sodium intake, and stress.
   
6. Humoral mechanisms: the autonomic nervous system as well as the rennin-angiotensin, kallikrein- kinin system and natriuretic peptide, plays an important role in the physiological regulation of short-term changes in blood pressure and have been medically implicated in the pathogenesis of essential hypertension.
   
7. Drugs: drugs such as steroids, hormonal contraceptives, some non-steroidal anti-inflammatory drugs (NSAIDs), carbenoxolone, liquorice, vasopressin and sympathomimetics have been shown to cause or aggravate hypertension.
   

Symptoms of Hypertension

1. Increase in cardiac output: this mainly occurs among young hypertensive patients. These patients normally experienced early increase in cardiac output, in association with increased pulse rate and circulating catecholamines. This normally results in changes in baroreceptor sensitivity, which would then operate at higher blood pressure level.
   
2. Changes in large arteries: there is thickening in the media, an increase in collagen and the secondary deposition of calcium. These alterations leads to loss of arterial compliance, which in turn leads to a more pronounced arterial pressure wave resulting into the development of Atheroma.
   
3. Left ventricular hypertrophy: this results from increased peripheral vascular resistance and increased left ventricular load.
   

In most cases, hypertension is generally termed as a symptomless disease. This is so because most often, some of the above common symptoms are non-specific and may not reflect levels of blood pressure. They can therefore, not be relied upon for the suspicion and diagnosis of hypertension or monitoring of blood pressure. The main focus of a clinical evaluation is to identify complications and look for evidence of secondary hypertension.