Blood pressure is the force exerted by circulating blood against the walls of the body's arteries. BP under 130/80 helps maintain general well being. Hypertension is actually a systemic disease. Although it is traditionally thought that the most damaging impact of hypertension is on the heart, the eyes, the kidneys, and especially the brain are affected.
Hypertension is the most important risk factor for strokes. Ischemic strokes, which account for about 87% of all strokes, result when an artery that supplies blood to the brain becomes blocked by a clot. In a thrombotic stroke, the clot forms in a diseased artery within the brain itself. In an embolic stroke, the clot forms outside the brain then breaks away and is carried by the blood to the brain, where it blocks a previously normal artery. Most emboli originate in the large vessels of the neck, the aorta, or the heart itself.
The sudden surge in BP in a hypertensive patient can lead to hemorrhagic strokes which are secondary to rupture of a blood vessel in the brain. Both systolic and diastolic hypertension contribute to risk; the higher your pressure, the higher your risk. According to one Harvard study, hypertension increases a person’s risk of stroke by 220%; according to another, each 10 mm Hg rise in systolic pressure boosts the risk of ischemic stroke by 28% and of hemorrhagic stroke by 38%.
Hypertension can also lead to transient ischemic attack or ministroke. Uncontrolled hypertension can lead to an aneurysm that is weakening and bulge of the vessel wall which can rupture and lead to subarachnoid haemorrhage, a potentially fatal medical condition.
A stroke can result in paralysis of the limbs, loss of speech, language dysfunction, visual impairment, difficulty swallowing, imbalance, memory issues and seizures. Brainstem strokes can lead to respiratory failure, ventilator dependence, coma state and in severe cases loss of life.
These major strokes have milder counterparts. MRI studies show that small microbleeds are much more common. Similarly, many people have tiny ischemic strokes, which are classified as lacunes which can be silent. Although a simple microbleed or lacune are not likely to produce symptoms, a series of these events can produce major problems, including memory loss called dementia. Hypertension can also cause nagging problems like irritability, trouble concentrating and general fatigability.
Controlling blood pressure through lifestyle changes, diet and medications can help one achieve optimal brain health.
(This article is attributed to Dr. Shobha N, Consultant - Neurologist And Stroke Physician, Manipal Hospital Malleshwaram)
(Disclaimer: The opinions expressed in this article are those of the author. They do not reflect the views of India TV)