- K1 -
- K2 -
- K3 -
- K4 - sounds becomes muffled
- K5 - fifth phase - is when sounds cease, as the artery is no longer compressed.
In some individuals, the sounds do not completely disappear and so the diastolic value is taken at K4, although K5 is preferred. The WHO recommend the use of phase IV to measure BP in pregnancy, while the US National Heart, Lung and Blood Institute recommends phase V.