Normal blood pressure for a healthy adult is ____________.

Normal blood pressure for a healthy adult is widely recognized as 120/80 mmHg. This reading reflects optimal cardiovascular health, with the first number (systolic pressure) measuring the pressure of blood in the arteries when the heart beats, and the second number (diastolic pressure) measuring the pressure when the heart is at rest between beats. Maintaining a blood pressure around this level is crucial as it indicates that the heart is working efficiently and the vascular system is not under excessive strain.

Values significantly outside of this range, as seen in the other options, can indicate various health issues. For instance, extremely low or high readings like 20/180 mmHg or 180/20 mmHg would suggest severe health problems requiring immediate medical attention, such as shock or hypertensive crises, respectively. Thus, the reference of 120/80 mmHg provides a benchmark for assessing overall health and potential risks related to cardiovascular conditions.