High blood pressure has detrimental effects on all organs of the body.
The heart musculature and blood vessels get thickened which require more blood and oxygen. The thickened blood vessels are unable to meet the increased demand making the patient prone to ischemic heart diseases like episodes of angina and heart attacks.
Sometime the heart is unable to pump against an increased blood pressure precipitating heart failure. Whatever blood is coming from the lungs to the heart cannot be pumped out to the other parts of the body.
As a result, fluid starts to accumulate in the lungs and the patient presents with severe shortness of breath.
This condition is called Left Ventricular Failure (LVF)
Sudden increase in blood pressure may cause unconsciousness and fits. This condition is called Hypertensive Encephalopathy Thickened blood vessels are prone to rupturing and if it occurs in the brain it can cause paralysis of any part of the body.
Visual impairment can result due to a lack of blood supply to the retina. This is a result of thickened blood vessels which are a consequence of high blood pressure. Kidneys can also be damaged by long standing high blood pressure.