References. 1  Shmerling RH. Approach to the patient with myalgia. http://www.uptodate.com/home. 2  LeBlond RF, et al., eds. The spine, pelvis and extremities. 3  Muscle cramps. Merck Manual Professional Version. 4  Sprains, strains and other soft tissue injuries. American Academy of Orthopaedic Surgeons.
Freebase(0.00 / 0 votes)Rate this definition: Hydronephrosis â literally water inside the kidney â refers to distension and dilation of the renal pelvis and calyces, usually caused by obstruction of the free flow of urine from the kidney. Untreated, it leads to progressive atrophy of the kidney.
Once urine is made, it flows into the kidney pelvis, down the ureter and into the bladder where it is stored. Once the bladder is full, it empties via the urethra. A blockage at any point along this pathway can lead to hydronephrosis.