Hold Pump to inflate the cuff from zero to wherever you want, then hit Release cuff to start deflating. Every round picks a brand-new hidden systolic and diastolic, so you'll hear the pulse sounds start and fade at a different spot each time. Note where that happened, then type in your reading and see how close you got.
0mmHg
Hold Pump to inflate the cuff.
What did you hear?
Enter both numbers first.
Systolic
Diastolic
You released the pump before reaching the actual systolic pressure — that likely cost you the first sound. Try pumping about 20–30 higher than you expect the systolic to be.