Kidneys are paired bean-shaped organs that are located on either side of the spine, under the rib cage towards the middle of the lower back. The main function of the kidneys is to filter out the wastes or toxins that are flushed out in the urine. They help in regulating the composition of the blood and maintain the balance of electrolytes and fluids in the body. Nephrons are the basic functional units of the kidneys and each kidney contains about a million nephrons. These are tube-like structures that perform the important function of filtering out substances from the blood so as to maintain the homeostatic balance of fluids. Nephrons also help in the absorption of substances that are needed for healthy functioning of the body. The regulation of pH levels, blood volume and the blood pressure depends on how well nephrons perform their functions. A loss of nephrons or abnormal nephron function is most likely to have an adverse effect on the kidney function. The affected kidney could even undergo atrophy. Causes The term 'atrophy' refers to the reduction in the size of an organ due to an ailment or disuse. So, an atrophic kidney is a medical condition that is characterized by the shrinkage in the size of one or both kidneys due to an inadequate blood supply to the kidneys and/or loss of nephrons. This condition is also referred to as renal atrophy. The loss of nephrons could also cause the renal arteries and veins to shrink. Renal diseases, urinary tract obstruction, acute pyelonephritis or any condition that impacts the nephron function in a negative manner could give rise to renal atrophy. Ischemia, which refers to the decreased supply of oxygen and nutrients due to inadequate blood flow to the kidneys, could also have an adverse effect on kidney function. Ischemia may occur due to atherosclerosis (narrowing of renal arteries due to accumulation of fatty deposits inside the arterial walls) or the formation of renal cysts. Renal artery occlusion, which is a blockage of the major arteries that supply blood to the kidneys, could also be caused by blood clots. Reflux nephropathy, which is a condition that is characterized by kidney damage due to the backflow of urine into the kidney, could also be a contributory factor for renal atrophy. Renal atrophy might also involve the thinning of renal parenchyma, which is the functional tissue of the kidney. It could be caused due to obstruction of the urinary tract due to an increased pressure on the tissues or compression of the intra-renal veins and arteries. Under these circumstances, one is most likely to experience symptoms that people afflicted by a urinary tract infection may experience. Painful urination, blood in urine and frequent urge to urinate are some of the symptoms that one might experience. Kidney atrophy is most likely to cause kidney pain as well. Obstructive uropathy, which is a condition wherein the interference with the normal urine flow leads to back pressure within the kidneys, can also cause damage to the nephrons. This could lead to chronic loss of function which may cause the kidneys to waste away and shrink in size. Diagnosis and Treatment For chalking out the treatment plan, doctors first need to determine the underlying cause of this condition. Sonography and intravenous urography might not always help in the diagnosis, however, imaging procedures such as CT scan and MRI can surely help in the diagnosis of renal atrophy. The treatment will basically depend on the extent of damage. In case of a urinary tract infection or acute pyelonephritis, use of medications might help, but if one is suffering from renal failure, the treatment will involve dialysis. One must also make certain lifestyle-related changes. Excessive consumption of alcohol can cause severe damage to the kidneys and make one prone to kidney disease, therefore it's recommended that you cut down on your intake of alcohol. If you are suffering from a renal disease, it would be better to increase your intake of water and follow a renal diet to keep your kidneys in a good condition. If you have been experiencing kidney pain, urinary symptoms or any of the aforementioned symptoms, seek medical assistance immediately. A timely medical treatment coupled with lifestyle modifications will surely help in alleviating the symptoms and will also lower the risk of complications in future. Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.