Normal blood pressure responses to the Valsalva maneuver

Normal Valsalva response:

Normal changes in systolic blood pressure during 10 seconds of straining (shaded).
Phase 1 - systolic blood pressure rises with initiation of the maneuver.
Phase 2 - systolic blood pressure returns to baseline after several seconds.
Phase 3 - systolic blood pressure drops below normal after strain is released.
Phase 4 - systolic blood pressure rises transiently before returning to baseline.

Graphic 78776 Version 4.0