Essential Hypertension

Essential hypertension is chronic high blood pressure with no identifiable cause. This type of hypertension affects 95% of sufferers. Several factors can put a person at higher risk of developing essential hypertension, such as:

• Obesity. People with a Body Mass Index (BMI) of over 25 account for over 85% of essential hypertension cases. People who are overweight have more fatty tissue, which increases the likelihood of fatty deposits forming in their arteries. This increases total peripheral resistance, which raises blood pressure.
• High cholesterol levels. Cholesterol is needed in the body for many different functions and is made in the liver from the food we eat. If the level of cholesterol in the blood is too high, this can cause it to build up in the artery walls and start to block them, a condition known as atherosclerosis.
• Sedentary lifestyle. People who are not very active have 50% higher risk of developing hypertension than those who have active jobs or take part in regular vigorous exercise. It is thought that this is because a sedentary lifestyle is strongly linked with obesity and an unhealthy diet with too much salt.
• Family history of hypertension. Having one or more family members with hypertension puts you at twice the risk of developing it.
• Ageing. As we get older, our arteries begin to lose their elasticity and begin to get thicker, with more collagen and calcium accumulation. This means that the arteries are less able to expand when high pressured blood flows through them, so blood pressure increases throughout the whole body.
• Salt sensitivity. This is when the kidneys are not able to clear salt effectively from the blood. High sodium levels in the blood cause retention of water, meaning that the overall volume of blood is higher, so the pressure in the vessels is higher. It is thought that decreased oestrogen production after the menopause is linked to increased salt sensitivity.
• High blood renin levels. Renin is a substance used by the body to raise blood pressure via the renin-angiotensin system.
• Sympathetic nervous system hyperactivity. The sympathetic nervous system is responsible for our “fight or flight” response. When it is activated, heart rate is increased, so cardiac output increases. This raises blood pressure.
• Excessive caffeine consumption. It is not known why this happens, but it is thought that it could be due to increased levels of adrenaline, or that caffeine may block a hormone that allows the arteries to dilate.

 

 

References

Medline Plus - "Essential Hypertension"

https://www.obesityaction.org/ - "Hypertension and Obesity"

https://www.nhs.uk/ - "Cholesterol"