What does the second number in a blood pressure reading signify?

In a blood pressure reading, the second number represents the diastolic pressure, which is the pressure in the arteries when the heart is resting between beats. This pressure signifies the phase of the cardiac cycle when the heart fills with blood, and it reflects the lowest level of pressure in the arteries.

Understanding the sounds associated with blood pressure measurements is crucial. As the cuff pressure decreases, the first sound that is heard corresponds to the systolic pressure, marking the pressure at which blood begins to flow through the artery again. The sound will continue until the blood flow becomes smooth and laminar, at which point the sounds disappear. This point denotes the cessation of sounds and is indicative of the diastolic pressure.

Therefore, the second number signifies the level of pressure in the arteries during the diastolic phase, where the heart is not contracting, providing an essential measure of cardiovascular health.