High blood pressure, also known as hypertension, is a common health condition but can lead to disabling consequences if not managed adequately. It is diagnosed when the blood pressure is persistently higher than 130/80 mmHg to 135/85 mmHg. ‘mmHg’ is the unit used to measure blood pressure and it is read as ‘millimeters of mercury’. For more information on the mechanism and measurement of high blood pressure, you may want to visit https://www.ncbi.nlm.nih.gov/books/NBK279251/.
Different people have different blood-pressure-lowering targets based on their health conditions. For example, for most people without any coexisting illness, the blood pressure target is less than 135/85 mmHg. However, the targets are further lowered to 130/80 mmHg for people with diabetes and less than 120/80 mmHg for people with coexisting heart or kidney disease. These targets are very important to meet to avoid complications of high blood pressure. Some of these complications are discussed below:
1) Brain damage
Persistently elevated blood pressure can lead to stiffening and thickening of the arteries (blood vessels supplying blood to different parts of the body). When this happens in the brain, it causes impairment in the flow of blood leading to brain damage. An example is dementia, however more disabling and even life-threatening consequence is stroke.
2) Damage in the eyes
Similar to the effect of high blood pressure on the brain, eyes can also be affected over time. This is called hypertensive retinopathy. The risk further increases if someone has co-existing diabetes because high levels of sugar in the blood damage blood vessels.
3) Peripheral artery disease
As explained above, uncontrolled high blood pressure can cause narrowing of the arteries supplying blood to the peripheral tissues and extremities (such as legs, fingers, and toes, etc.). One such condition is intermittent claudication. It is characterized by pain, cramping, tingling and numbness among other symptoms and occurs due to reduced blood supply to the muscles.
4) Heart disease
The heart pumps blood into a big blood vessel called the aorta, which then branches and supplies blood to the rest of the body. High blood pressure in the aorta causes the heart to pump harder so that blood can be sent to the entire body. Over time, this results in changes in the structure of the heart, such as an increase in its size leading to heart failure. Furthermore, narrowing of the blood vessel (coronary artery) supplying blood to the heart can increase the risk of conditions like Coronary Artery Disease and heart attack.
5) Kidney disease
Hypertensive nephropathy is a condition whereby the kidneys are damaged due to impaired blood supply as a result of persistently elevated blood pressure. Consequently, the ability of the kidneys to excrete metabolic waste decreases and leads to the accumulation of undesired substances in the body.