What is high blood pressure (hypertension)?

Understanding High Blood Pressure (Hypertension)

High blood pressure (hypertension) is a condition where the force of blood against artery walls is consistently too high, which can lead to serious health problems including heart disease, stroke, kidney disease, and dementia if left untreated. 1

Definition and Classification

• Hypertension is defined as persistent systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥90 mmHg according to most guidelines 1
• The American Heart Association classifies blood pressure as follows 1:
  • Normal: <120/80 mmHg
  • Prehypertension: 120-139/80-89 mmHg
  • Stage 1 hypertension: 140-159/90-99 mmHg
  • Stage 2 hypertension: ≥160/100 mmHg 1
• Blood pressure is a continuous variable with no clear threshold where cardiovascular risk begins - risk increases progressively throughout the range of blood pressure 1

Prevalence and Impact

• Hypertension affects approximately one-third of the adult population in the United States 1
• The prevalence increases with age, affecting more than 75% of people by their 80s 1
• Hypertension is now more prevalent in low-income and middle-income countries than in high-income countries 1
• In 2015, an estimated 8.5 million deaths were attributable to high blood pressure worldwide 1
• Hypertension often goes undiagnosed - up to 33% of young men with hypertension are unaware of their condition 1

How High Blood Pressure Affects Your Body

• The increased pressure on artery walls can damage blood vessels and organs throughout the body 1
• Target organ damage affects primarily 2:
  • Heart: leading to coronary artery disease, heart failure, and left ventricular hypertrophy
  • Brain: increasing risk of stroke and dementia
  • Kidneys: causing chronic kidney disease and renal failure
  • Eyes: resulting in hypertensive retinopathy
  • Blood vessels: accelerating atherosclerosis and arterial damage

Causes and Risk Factors

• Primary (essential) hypertension: No identifiable cause, develops gradually over years 1
• Secondary hypertension: Results from an underlying condition such as kidney disease, adrenal gland tumors, thyroid problems, or certain medications 2
• Risk factors include 1:
  • Age (risk increases with advancing age)
  • Family history and genetic factors
  • Obesity and excess weight
  • Physical inactivity
  • High sodium (salt) intake
  • Low potassium intake
  • Excessive alcohol consumption
  • Tobacco use
  • Stress
  • Certain chronic conditions (diabetes, sleep apnea, kidney disease)

Symptoms

• Hypertension is often called the "silent killer" because most people have no symptoms, even at severely elevated levels 2
• Some people may experience headaches, shortness of breath, or nosebleeds, but these typically don't occur until blood pressure reaches severely high levels 2
• In cases of hypertensive emergency (severe elevation with organ damage), symptoms may include severe headache, vision problems, chest pain, difficulty breathing, seizures, or confusion 3

Diagnosis

• Blood pressure is measured using a blood pressure cuff (sphygmomanometer) 1
• Proper measurement technique is crucial for accurate readings 1:
  • Patient should be seated quietly for 5 minutes before measurement
  • Arm should be supported at heart level
  • Appropriate cuff size should be used
  • Multiple readings should be taken and averaged
• Diagnosis requires elevated readings on multiple occasions 1
• Home blood pressure monitoring and 24-hour ambulatory monitoring can provide additional valuable information 1

Complications of Untreated Hypertension

• Heart attack and heart failure 1, 4
• Stroke 1, 4
• Aneurysm 1
• Kidney damage and failure 1, 4
• Vision loss due to damaged blood vessels in the eyes 2
• Cognitive decline and dementia 1
• Sexual dysfunction 1

Prevention and Management

• Lifestyle modifications are the foundation of prevention and treatment 5:

  • Maintain a healthy weight (BMI 18.5-24.9) 5
  • Follow a heart-healthy diet (DASH diet) low in sodium and high in potassium 5
  • Regular physical activity (at least 30 minutes most days of the week) 6
  • Limit alcohol consumption 5
  • Quit smoking 5
  • Manage stress 5

• Medications may be necessary when lifestyle changes aren't enough 5:

  • First-line medications include thiazide diuretics, ACE inhibitors, ARBs, and calcium channel blockers 5, 7
  • Medication choice should be based on individual factors including age, race, and comorbidities 5

• Regular monitoring is essential to ensure blood pressure remains controlled 1

When to Seek Emergency Care

• Seek immediate medical attention for severely elevated blood pressure (>180/120 mmHg) with symptoms such as 1, 3:
  • Severe headache or confusion
  • Vision problems
  • Chest pain
  • Difficulty breathing
  • Seizures
  • Weakness or numbness

Understanding high blood pressure and taking steps to control it can significantly reduce your risk of serious health complications and improve your overall quality of life.