Hypertension

Hypertension
Field	Cardiology, Internal medicine
Complications	Myocardial infarction, Stroke, Chronic kidney disease
Types	Primary hypertension, Secondary hypertension
Risks	Obesity, Diabetes mellitus, Family history
Diagnosis	Sphygmomanometer
Treatment	Lifestyle modification, Antihypertensive drug
Medication	ACE inhibitor, Calcium channel blocker, Diuretic

Hypertension. It is a chronic medical condition characterized by persistently elevated pressure in the arterial system. Often termed the "silent killer," it is a major modifiable risk factor for Cardiovascular disease, Cerebrovascular accident, and End-stage renal disease. The condition is typically defined by measurements obtained using a Sphygmomanometer and is classified based on thresholds established by organizations like the American Heart Association.

Definition and classification

Diagnostic thresholds are primarily based on measurements of Systolic blood pressure and Diastolic blood pressure. Major guidelines, such as those from the European Society of Cardiology, provide specific numerical criteria for staging the condition. The condition is broadly categorized into Primary hypertension, which has no identifiable cause, and Secondary hypertension, which results from an underlying disorder. Common systems for classification include those published in the Journal of the American College of Cardiology, which help guide therapeutic strategies. The World Health Organization also contributes to global diagnostic standards, emphasizing the public health burden.

Causes and risk factors

For Primary hypertension, etiology is multifactorial, involving a complex interplay of genetic and environmental factors. Key modifiable risk factors include high dietary sodium intake, Physical inactivity, Alcohol abuse, and Tobacco smoking. Non-modifiable risks encompass advanced age, Family history, and specific ethnic backgrounds, such as those of African descent. Secondary hypertension can arise from identifiable conditions like Renal artery stenosis, Primary aldosteronism, Cushing's syndrome, Pheochromocytoma, and Coarctation of the aorta. Other contributing diseases include Obstructive sleep apnea and chronic use of NSAIDs.

Pathophysiology

The fundamental mechanism involves an increase in Peripheral vascular resistance or Cardiac output, often both. Key regulatory systems include the Renin–angiotensin–aldosterone system (RAAS), the Sympathetic nervous system, and endothelial function via Nitric oxide. Dysregulation of the RAAS, often involving overactivity of Angiotensin II, leads to Vasoconstriction and increased Blood volume. Structural changes in the arterioles, termed Vascular remodeling, perpetuate elevated resistance. The role of the Kidney in sodium and water homeostasis, as described in the work of Arthur Guyton, is central to long-term pressure control.

Diagnosis

Accurate diagnosis relies on proper technique using a validated Sphygmomanometer, with increasing use of Ambulatory blood pressure monitoring and Home blood pressure monitoring to avoid White coat hypertension. Clinical evaluation includes a thorough Medical history and Physical examination to assess for End-organ damage. Investigations often include an ECG, Echocardiography, Urinalysis, and blood tests for Serum creatinine and Potassium. Screening for causes of Secondary hypertension may involve assays for Plasma renin activity and Aldosterone, or imaging studies like Computed tomography angiography of the Renal arteries.

Management

First-line intervention involves Lifestyle modification, including adoption of the DASH diet, Sodium restriction, regular Aerobic exercise, and Weight loss. When pharmacological therapy is required, first-line agents typically include thiazide diuretics, ACE inhibitors, ARBs, and calcium channel blockers. Treatment goals are defined by guidelines from bodies like the American College of Cardiology and often aim for specific Blood pressure targets. Resistant cases may require combination therapy or referral to a specialist in hypertension at an institution like the Cleveland Clinic.

Epidemiology

It is a leading global risk factor for mortality and is estimated to affect over a billion individuals worldwide according to the Global Burden of Disease Study. Prevalence rises sharply with age and varies significantly by region, with high rates noted in many Low- and middle-income countries. Significant disparities exist, with higher prevalence and poorer control observed among populations in Sub-Saharan Africa and certain groups in the United States. Major awareness campaigns are spearheaded by organizations such as the World Hypertension League and the Centers for Disease Control and Prevention to improve detection and management.

Category:Cardiovascular diseases Category:Risk factors