Diastolic blood pressure measures the force of blood on the walls of the:

Diastolic blood pressure is measured when the heart is in a state of relaxation between beats, specifically during the diastole phase of the cardiac cycle. This reading reflects the pressure in the arteries at this moment, indicating how much pressure blood exerts on arterial walls when the heart is not contracting.

Understanding this context is crucial as it emphasizes the importance of arterial health. If the arteries have stiff or narrowed walls, the diastolic blood pressure may be affected, potentially leading to complications such as hypertension. The other types of vessels, such as veins and capillaries, do not experience blood pressure readings in the same way arteries do, because they operate under different dynamics and their roles in circulation are distinct from that of the arteries during the cardiac cycle. Similarly, the heart chambers are where the blood is pumped and stored rather than being subjected to the same pressure measurements as the arteries. This makes the arterial system the primary focus for measuring diastolic blood pressure.