Over time, someone who has persistently high blood pressure is more likely to develop health complications as a result.
These can vary in severity, and include:
- heart disease
- aortic aneurysm
- peripheral arterial disease
- kidney disease
- loss of vision
- and vascular dementia
Here, we’ll examine how hypertension causes these complications in more detail, and discuss what steps someone can take to prevent them, by looking after their blood pressure.
High blood pressure can lead to hypertensive heart disease, which can take on several forms.
Coronary heart disease (also referred to as ischaemic heart disease) occurs when the arteries surrounding the heart become clogged up with fatty debris, called atheroma or plaque. This leads to the arteries becoming stiffer and narrower, and obstructs the flow of oxygenated blood to the heart. The process is known as atherosclerosis. High blood pressure, by damaging the walls of the arteries, makes them more susceptible to atherosclerosis.
CHD can cause a heart attack, where the blood supply to the heart is suddenly cut off. This is where an atheroma bursts, which produces a blood clot in the artery and blocks blood flow. Consequently, the heart muscles will start to die without immediate medical attention.
Heart failure is when the heart loses the capacity to pump blood around the body efficiently. This has the cyclical effect of making the heart work even harder to try and get blood out. In an effort to adapt to this reduction in pumping strength, the tissues in the heart will stretch to try and increase the volume of blood it can retain, which causes the heart’s pumping action to become further weakened.
Hypertension induces this through a process called left ventricular hypertrophy. This is where the heart muscle becomes larger and stiffer (through having to work harder all the time) and cannot rest as well between heartbeats.
During a stroke, oxygen supply to the brain is partially cut off. Without oxygen, brain cells start to expire, and this can cause lasting damage.
This may be due to the formation of a blood clot in a supplying vessel (ischaemic), or a vessel in the brain rupturing (haemorrhagic).
The NHS estimates that 85 percent of strokes are ischaemic. The Stroke Association state that hypertension is the single most prominent risk factor in strokes, and is responsible for roughly half of all ischaemic cases. However, high blood pressure can also cause haemorrhagic strokes too.
Once again, high blood pressure causes strokes by causing arteries to become stiff and susceptible to atherosclerosis, which both raises the risk of blood clots, and of blood vessels bursting and leaking in the brain.
The aorta is a thick blood vessel which is connected to the heart, and runs down into the abdomen. As it is the main conduit between the heart and the rest of the body, it carries high volumes of blood.
An aortic aneurysm occurs when one of the walls of the aorta becomes weakened. This leads to the high volumes of blood passing through pressing against the weakened region, and this can cause the aorta to become swollen.
Signs of an aneurysm include back pain, pain in the abdomen, and a throbbing sensation in the stomach. If an aneurysm is not treated, it can lead to a rupture in the aorta, which can often be fatal.
High blood pressure can lead to an AAA, by weakening the aorta wall, and through atherosclerosis.
The condition sometimes referred to as PAD or PVD (peripheral vascular disease), is caused by the development of plaque in the arteries providing blood to the legs.
This can cause pain in the legs, and occasionally other symptoms such as: loss of sensation in the legs; ulcers; and muscle shrinkage. These will typically manifest gradually over time.
In the majority of cases PAD is caused by atherosclerosis; which, as described above, can occur as a result of high blood pressure. It is a sign of cardiovascular illness, so someone with symptoms should be seen by a doctor.
Essentially, the kidneys work to cleanse the blood by filtering out waste. To do this, the kidneys need blood vessels.
In someone who has had high blood pressure for a long time, the arteries and capillaries leading to the kidneys can become strained and stiff, meaning that blood cannot flow through and reach the kidneys as easily.
As this problem becomes more severe, the kidneys will lose some ability to function properly, and be less able to filter out waste from the blood. Over time this can lead to kidney damage, which can also have the cyclical effect of making high blood pressure worse.
Persistent high blood pressure can cause damage to the blood vessels in the eyes (of which there are many).
Retinopathy is where blood flow to the retina become inhibited. After several years, this can affect vision and eventually lead to sight loss.
Optic neuropathy is, again, the result of improper blood flow to the optic nerve. This leads to nerve cells expiring, causing loss of sight.
This is a condition caused by inhibited blood flow to the brain, as a result of damaged blood vessels.
The brain requires a continuous supply of blood and oxygen to function properly. When blood flow to it is reduced, because of leaking blood vessels or blockages, brain cells may die.
This can lead to symptoms such as:
- not being able to concentrate or think as clearly
- mood or personality changes
- coordination problems
- and memory problems.
Vascular dementia is most common in over 65s, and tends to be a progressive condition. There is no cure but treatments are available that can help to slow this progression down.
Managing and preventing high blood pressure
If you have high blood pressure, you can reduce the risk of developing complications by ensuring you adhere to your high blood pressure treatment plan, as set out by your doctor; and by monitoring your blood pressure regularly to make sure it is under control.
If you don’t have high blood pressure, you can reduce your risk by maintaining a healthy diet and lifestyle, and getting plenty of exercise.
Follow the links below to find out more about treating and preventing high blood pressure.