Shockwaves are mainly used in the body to break up stones, most commonly kidney stones. Kidney stones in the renal pelvis may cause localized swelling and pain, which may be shattered after shockwave treatment. After fragmentation, smaller stones are formed, which may be passed down the urethra. However, the stone may become embedded in the narrowing of the urethra, which may lead to localized congestion and edema and more severe pain. This requires an ultrasound of the kidneys to prevent pain from the stone dislodging into the stricture of the ureter. Drinking plenty of fluids, progesterone injections, and exercise can also be used to promote hormone elimination and relieve pain.