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.
Hydronephrosis is a condition that typically occurs when one kidney becomes swollen due to the failure of normal drainage of urine from the kidney to the bladder. This swelling most commonly affects only one kidney, but both can be involved. Hydronephrosis is not a disease but a structural condition.his backflow of urine is called vesicoureteric reflux. Other causes of blockage may include: 1  a kink in the urteropelvic junction (where the ureter meets the pelvis of the kidney). 2  tumors in or near the ureter. 3  narrowing of the ureter from an injury or birth defect.