Which term describes low blood pressure?

• A. Hypotension
• B. Hypertension
• C. Edema
• D. Cyanosis

Answer: (A)

Low blood pressure is called hypotension. The prefix hypo- means below or less, and tension refers to pressure, so hypotension literally describes pressures that are lower than normal in the circulatory system. Clinically, it’s often considered when systolic pressure is around 90 mmHg or lower or diastolic pressure is around 60 mmHg or lower, though symptoms and context matter. Hypotension can cause lightheadedness or fainting from reduced blood flow to the brain, but some people live with naturally low pressures without issues. The other terms describe different conditions: hypertension is high blood pressure; edema is swelling from excess fluid in tissues; cyanosis is a bluish discoloration of the skin due to low oxygen in the blood.