Hypertension – what you need to know.

Hypertension means high blood pressure (BP). The normal blood pressure is around 120/80mmHg. The first number represents the pressure generated by the heart as it pumps. The second number represents the pressure remaining in the arteries when the heart relaxes.

Hypertension generally refers to systolic hypertension i.e. the first number is high, usually above 140mmHg. There is most commonly no underlying cause for this in 80-90% of cases and it is known as Essential Hypertension. Occasionally in young patients, an underlying cause may be identified such as:

1. Renal artery stenosis – this is a narrowing of the blood supply to the kidney. The kidney thinks there is not enough pressure in the blood and releases hormones to increase the blood pressure.
2. Phaeochromocytoma – this is a typically benign growth of the adrenal glands which secrete too much adrenaline (the “flight or fight” hormone) which increases blood pressure
3. Coarctation of the aorta – This is a narrowing of the main pipe that exits the heart, usually just after the branch that supplies the left arm (the left subclavian artery – LSCA). The narrowing lowers the BP towards the kidneys and other organs; the heart responds by increasing the pressure it generates to force blood past the narrowing and this higher pressure can therefore be measured in the arm.

CT and MRI imaging plays a critical role in diagnosing the above conditions and cardiac MRI and CT in particular can identify complications in the heart from high BP such as:

1. Abnormal thickening of the heart muscle (left ventricular hypertrophy or LVH) which can be a precursor to heart failure
2. Aneurysms of the aortic root and aorta
3. Quantification of aortic regurgitation (backward leakage of blood through the aortic valve into the heart caused by high pressures in the aorta)

Hypertension is additionally a recognised risk factor for heart attacks, strokes, kidney and eye problems so it is important to detect it early.

If you are concerned about hypertension or would like to discuss anything above, then book in for an appointment using the link above.

Sept 2025