Final answer:
A unilateral small scarred kidney can be caused by nephrotic syndrome, pyelonephritis, and renal failure, among other conditions. These diseases lead to a reduction in kidney size and function through different mechanisms such as damage to the glomeruli, infections, and overall renal dysfunction.
Step-by-step explanation:
A unilateral small scarred kidney, also known as a shrunken kidney, can result from various conditions that affect the kidney structure and function over time. Three common causes are:
- Nephrotic syndrome: This involves damage to the glomeruli, which are the filtering units of the kidney. When damaged, they allow proteins that are normally retained in the blood to pass into the urine, leading to proteinuria, swelling, low serum albumin, and high cholesterol levels.
- Pyelonephritis: An infection of the kidneys usually resulting from a urinary tract infection. This can lead to scarring and shrinkage of the kidney if repeated or chronic infections occur.
- Renal failure: Also known as kidney failure, it occurs when the kidneys are unable to function adequately. This can result from various conditions, including the progression of chronic kidney diseases or severe acute kidney injury.
Other non-infectious causes such as diabetic nephropathy, kidney stones, and certain kidney tumors like renal cell carcinoma can also contribute to a unilateral small scarred kidney.