How does Polycystic Kidney Disease cause Protein in Urine

Symptoms of PKD usually start by 2nd or 3rd decade of life. Protein in urine is one of the symptoms that may present in PKD patients. How does this occur?

PKD is the most common, inherited cystic kidney disease. It is caused by genetic defects, which result in the growth of thousands of cysts in the kidneys.
Bilateral kidneys are affected. Autosomal Dominant PKD is the most common inherited form, which accounts for 8%~10% of end-stage renal disease. Symptoms usually start by 2nd or 3rd decade of life. Protein in urine is one of the symptoms that may present in PKD patients. How does this occur?

The kidneys are responsible for cleansing the blood by filtering waste materials from the body and maintaining a normal balance of fluids and chemicals in the body. Each kidney is bean-shaped and about the size of a large orange.

The tiny filters of the kidneys are known as glomeruli, and one filter is called a glomerulus. The structure of the glomerulus allows wastes and some water and salt to pass from the blood into a tubule, while keeping things that the body need like blood cells and protein in the bloodstream.

Normally, protein is not removed from the blood when the kidneys filter wastes from the blood. However, due to the compression and squeeze of gradually enlarged cysts, the normal kidney intrinsic cells and tissues are damaged.

When the kidney filters are impaired, proteins can be released into urine. Proteinuria is the term used to describe excessive amounts of protein in urine.

When proteinuria become more evident as the disease progresses, people with PKD will detect symptoms of foamy urine and swelling (edema). Excess protein can lead to the urine to foam in water, as protein changes the surface tension between urine and water. Edema often only happens in nephrotic range proteinuria.

Hypertensive persons who develop protein in urine stand a significant chance for Kidney Failure. So once detect this symptom, patients should seek effective treatment promptly.