14.3: Alterations in Blood Pressure

Alterations in blood pressure, such as hypertension (high blood pressure) and hypotension (low blood pressure), significantly affect human health. Understanding these conditions' classifications, causes, and symptoms is essential for effective management and treatment.

Hypertension (High blood pressure)

Hypertension occurs when blood pressure readings consistently exceed the normal range. It is diagnosed when systolic blood pressure (the top number, indicating pressure while the heart beats) exceeds 130 mmHg, and diastolic pressure (the bottom number, indicating pressure between beats) surpasses 80 mmHg on two separate occasions.

• • Symptoms: Individuals with hypertension may experience symptoms such as blurry or double vision, nosebleeds, and palpitations. However, many people with hypertension do not exhibit noticeable manifestations, earning it the nickname "the silent killer."
• • Classification:
  1. Primary (essential) hypertension: This type has no identifiable cause but is linked to risk factors such as smoking, obesity, genetic predisposition, age, and high salt intake.
  2. Secondary hypertension: This form is caused by underlying conditions affecting organs or systems, such as kidney disease (e.g., polycystic kidney disease) or endocrine disorders (e.g., hyperthyroidism).

Hypotension (Low blood pressure)

Hypotension is identified when systolic blood pressure falls below 90 mmHg, and diastolic pressure drops below 60 mmHg. This condition may lead to inadequate blood flow to organs, resulting in various symptoms.

• • Symptoms: Common symptoms include dizziness, fatigue, increased sweating, and tachycardia (rapid heart rate). These symptoms arise because the body's organs are not receiving sufficient oxygen and nutrients due to reduced blood flow.
• • Classification:
  1. Orthostatic hypotension occurs when blood pressure drops abruptly upon sudden standing up from a sitting or lying position, leading to dizziness or lightheadedness.
  2. Postprandial hypotension: A significant decrease in blood pressure following a meal, particularly common in older adults.
  3. Neurally mediated hypotension: Occurs from prolonged standing, leading to miscommunication between the heart and the brain, resulting in decreased blood pressure.