1. Phase I—The first appearance of faint, repetitive, clear tapping sounds which gradually increase in intensity for at least two consecutive beats is the systolic blood pressure. 2. Phase II—A brief period may follow during which the sounds soften and acquire a swishing quality. 3. Phase III—The return of sharper sounds, which become crisper to regain, or even exceed, the intensity of phase I sounds. 4. Phase IV—The distinct abrupt muffling of sounds, which become soft and blowing in quality. 5. Phase V—The point at which all sounds finally disappear completely is the diastolic pressure.