Kidney Size and Health...what are normal dimensions? What c

Kidney size is not affected by body build. The kidneys grow at the same rate that the entire body grows, until physical development halts at around 25-26. It is at this point that internal organs reach their final dimensions. The mean dimensions of the kidneys upon maturation are: length-about 12cm, breadth-about 6cm and thickness-about 3cm. The weight of one kidney averages about 120-150 g. Any decrease in size (atrophy) is not normal. Increasing the size of a kidney is normal only in cases when one kidney is removed and the remaining kidney enlarges to compensate for the functional absence of the first.


Kidneys become enlarged during infections due to "edema". Infection causes inflammation (nephritis) and one of the main characteristics of the inflammation is edema. Edema is an increased amount of liquid among the cells. This occurs due to the increased permeability of the capillaries. During nephritis, all the kidneys’ structures become enlarged because of such edema. Typical symptoms/signs of acute renal (kidney) infection are lower back pain and high fever. Frequent urination and itching during urination are also present. This condition is serious and must be treated in a hospital with antibiotics, symptomatic and supportive therapy.


In cases of blockage (stone, tumor), urine collects in the renal calices and renal pelvis to cause inflammation. If blockage lasts too long, the renal calices, pelvis, and ureter above the blockage become extended. The collected urine has no place to go and creates pressure on the renal structures that surround the pelvis and calices (medulla and cortex). If a blockage lasts too long, urinary pressure can cause atrophy of those structures. This condition is called "hydronephrosis". A kidney with hydronephrosis loses its function after time. Blockages of the urinary tract are often followed by infections because normally, the urine flow mechanically cleans the urinary tract of all bacteria. If the blockage is caused by a stone, severe lower back pain is the first and most typical symptom. Frequent urination, itching, blood in the urine are also symptoms of a blockage. If there is infection, fever can be also present. This condition is treated with analgesics and spasmolitics to reduce the pain. Further treatment includes hyper-hydration to stimulate urination for stone expulsion. If hyper-hydration doesn’t help, the stone can be broken via ultrasound or removed surgically. If the stone is not expelled from the ureter, in time it will cause hydronephrosis and renal failure. If both kidneys are affected the only treatment is haemodializis ,or a kidney transplantation.