23. The bottom number is the diastolic number.
In between each beat of your heart, the arteries relax and wait to be filled with more blood. Then, it gets pumped throughout your body. This episode is diastole, and as you may have guessed, the lower number of your blood pressure. The diastolic number is the pressure in the arteries when the heart rests between beats. This is the time when the heart fills with blood and gets oxygen.
When your arteries do not have blood pushing through them, there is less force working against the arterial walls. As such, the diastolic number is lower than the systolic number. Ideally, you want your diastolic number to be below 80 when you are resting. Anything above 80 is entering into the dangerous territory for high blood pressure. Speak to your doctor if this seems to be a consistent concern.