Final answer:
Hypotension is defined as having a systolic blood pressure lower than 90 mm Hg, which can cause symptoms like dizziness and fainting. Blood pressure readings consist of systolic over diastolic values, and persistent low systolic pressure may signal an underlying health issue.
Step-by-step explanation:
Hypotension refers to lower-than-normal blood pressure, specifically when the systolic pressure (the top number in a blood pressure reading) is less than 90 millimeters of mercury (mm Hg). Systolic pressure measures the force of blood against artery walls when the heart beats or contracts; it is contrasted with diastolic pressure, which occurs when the heart is at rest between beats.
Blood pressure readings consist of these two figures, represented as systolic/diastolic (e.g., 120/80 mm Hg). A consistently low systolic reading can lead to symptoms such as dizziness or fainting, as inadequate blood flow fails to deliver enough oxygen and nutrients to the body's tissues and organs. While blood pressure may fluctuate throughout the day depending on various factors like stress levels, nutrition, and exercise, sustained hypotension may require medical attention to address underlying causes or to prevent potential complications. Careful monitoring of blood pressure, for those with known hypotension or hypertension, is important for maintaining overall cardiovascular health.