Hypertension
A sustained rise in systemic arterial pressure that is usually clinically silent because vessels adapt gradually with no acute pain signal, so screening and end-organ assessment (not symptoms) drive both diagnosis and the urgency of treatment.
First principles
Blood pressure is cardiac output times resistance
Arterial pressure equals cardiac output multiplied by systemic vascular resistance. In essential (primary) hypertension, no single lesion is responsible; instead, overactivity of the renin-angiotensin-aldosterone system and the sympathetic nervous system, increasing arterial stiffness, and impaired renal sodium handling combine to raise resistance and circulating volume over years. Because multiple systems drive it in parallel, hypertension is usually multifactorial rather than caused by one identifiable abnormality, which is why it is called essential rather than secondary in the great majority of cases.
Educational content pending clinical review. Not medical advice.