Less commonly, cystitis may occur as a reaction to certain drugs, radiation therapy or potential irritants, such as feminine hygiene spray, spermicidal jellies or long-term use of a catheter. Cystitis may also occur as a complication of another illness. The usual treatment for bacterial cystitis is antibiotics.
The maneuver is based on the fact that when a patient forcibly exhales against a closed nose and mouth while bearing down, as if having a bowel movement, specific changes occur in blood pressure and the rate and volume of blood returning to the heart.
Variations of the maneuver can be used either in medical examination as a test of cardiac function and autonomic nervous control of the heart, or to clear the ears and sinuses (that is, to equalize pressure between them) when ambient pressure changes, as in diving, hyperbaric oxygen therapy, or air travel.