Distinguish between primary (essential) and secondary hypertension.
• Essential hypertension represents 90% to 95% of cases of hypertension and is a complex, multifactorial disorder resulting most likely from the combined effect of mutations or polymorphisms at several gene loci (e.g., sodium resorption, renin-angiotensin system, aldosterone) in association with a variety of environmental influences.
• Secondary hypertension is caused by diseases of the kidneys or endocrine glands. Underlying causes are treatable:
-chronic renal failure
-renal artery stenosis
-coarctation of the aorta