Final answer:
A critical change in systolic blood pressure is when the measurement reaches 140 mm Hg or higher, indicating hypertension, which significantly increases the risk of serious health events like heart attacks and strokes. Hypertension starts at 130/80 mm Hg, while normal blood pressure is below 120/80 mm Hg.
Step-by-step explanation:
A critical change in systolic blood pressure considers significant shifts either towards hypertension or hypotension. According to the American College of Cardiology and American Heart Association guidelines, normal blood pressure is less than 120/80 mm Hg. An elevated systolic pressure falls between 120-129 mm Hg, while hypertension is defined at a threshold of 130/80 mm Hg or higher. A critical increase in systolic blood pressure is typically defined as a measurement of 140 mm Hg or higher, which is considered a clear indicator of hypertension. Conversely, a systolic blood pressure that is too low can lead to symptoms like fainting.
Chronically elevated systolic blood pressure increases the risks of heart attack, stroke, aneurysm, peripheral arterial disease, chronic kidney disease, and heart failure. As such, systolic pressure above the 140 mm Hg mark is considered a critical concern and requires medical intervention.