Sandbox:Kavya

# Hypertension

## Overview
Arterial blood pressure (BP) is a measure of the force exerted by the blood on the arterial walls. It is the function of both the cardiac output (CO) and the systemic vascular resistance (SVR). The maintenance of a normal blood pressure value is crucial to ensure appropriate blood circulation throughout the cardiovascular system. Arterial BP is considered one of the most important vital signs in the clinical setting.
Hypertension (HTN) is generally defined as an elevated systolic blood pressure (SBP)  140 mmHg and/or diastolic blood pressure (DBP)  90 mmHg at each of two or more visits. However, target BP values are set at a lower threshold in specific populations, such as diabetics and subjects with significant proteinuria and other renal diseases.

## Pathophysiology
Although the pathophysiology of secondary hypertension has been outlined, there is still much debate about the true pathogenesis of primary (essential) hypertension. It is now conceded that hypertension is caused by multiple genetic and environmental factors with varying roles between individuals.

## Diagnosis
- History:
Thorough history-taking is crucial for the diagnosis and assessment of hypertension. Not only should history-taking be targeted to identify symptoms consistent with high blood pressure, but more importantly it should address risk factors and target organ damage. History-taking alone may be sufficient to diagnose some causes of secondary hypertension, such as drug-induced hypertension, and may guide healthcare providers towards individualized work-up and tailored management.
- Blood Pressure Measurement:
The use of a sphygmomanometer in the clinic to measure blood pressure is the most accurate technique to diagnose hypertension. Blood pressure measurements must be performed appropriately according to a standardized technique that involves adequate device and cuff choice and comfortable positions. Sources of error, involving the sphygmomanometer, the patient, and the technique itself must also be considered and avoided. Other techniques for diagnosis, such as ambulatory and self blood pressure measurements may also be helpful, particularly for the follow-up of patients with hypertension.
- Electrocardiography:
An electrocardiogram (EKG/ECG) is performed to evaluate for the presence of left ventricular hypertrophy or silent myocardial infarction.

## Treatment
- Lifestyle Modification:
Hypertension is the most common primary diagnosis in America. Initial treatment for hypertension generally involves lifestyle modifications (nonpharmacologic therapy), which is also critical 
for prevention of the disease.
- moderate dietary salt restriction
- maintain body weight or weight reduction in obese patients
- increased intake of fruits and vegetables and low-fat dairy products
- limited alcohol intake, and regular aerobic exercise
Although effective control of blood pressure can be achieved in most patients with hypertension, the majority will require 2 or more antihypertensive drugs.
- Medical Therapy:
Medical therapy is considered the most efficient means for the reduction of both systolic and diastolic blood pressure values in patients with hypertension. The two most important approaches for pharmacologic therapy in hypertension are proposed by JNC-7 guidelines in 2004 and more recently by the ESH/ESC guidelines in 2013. With the emergence of recent data, a major shift from the classical use of thiazide-type diuretics as first line therapy for patients with isolated essential hypertension has occurred. Recent guidelines currently encourage the use of any anti-hypertensive agent for isolated essential hypertension. Nonetheless, various conditions warrant the use of specific classes that have been found to have compelling indications in certain diseases and among specific patient populations.