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.
There are many causes of hydronephrosis. In adults, the conditions that most often cause hydronephrosis include: 1  Kidney stones âSalts and minerals that are present in urine can form small hard stones that may become lodged in the kidneys or urinary tract.ther possible causes of hydronephrosis include: 1  Blood clots in the kidney or ureter. 2  Narrowing or stricture of the urinary tract due to injury, infection, birth defects or surgery.