Diuretics are the first drug group used with sodium restriction and thiazide diuretics are very effective in patients with mild to moderate hypertension. Loop diuretics are used when the kidneys are not functioning properly and spironolactone may be used in cases of hyperaldosteronism. Drugs that alter sympathetic nervous system affects on blood pressure are often a second stage treatments. When it affects the coronary arteries , it is the underlying cause of most heart attacks and a common cause of congestive heart failure and arrhythmias . The pathological process begins very early with a fatty streak composed of lipid deposited in the intima of arteries.
Modified macrophages known as foam cells accumulate in the plaque region.
These foam cells accumulate lipids , especially oxidized low-density lipoproteins . When the lesion becomes infiltrated with fibrous material it protrudes into the lumen of the artery. The lesion itself rarely occludes the artery but rather it is blood clots that form on top of the plaque that close off the channel. Chronic lesions become calcified and the elasticity of the vessel is decreased. This hardening of the arteries causes an increase in resistance to blood flow and therefore an increase in blood pressure .