Understanding Kidney Disease


The kidneys are bean-shaped organs about the size of a fist located near the middle of the back just below the rib cage. All the blood in the body passes through the kidneys several times a day removing waste. The waste products and any extra water the body doesn't use then become urine, which flows to your bladder where it is stored until you go to the bathroom.

The waste products in the blood come from normal activity of the body and from digesting food. Your body uses the food for energy and self-repair, and after it has taken what it needs, waste products are sent to the blood. If your kidneys did not remove these waste products, they would build up and damage the body. The actual filtering of the blood occurs in tiny units inside your kidneys called nephrons. Each kidney has about 1 million nephrons. The nephron contains a glomerulus which is a tiny blood vessel that intertwines with a tiny urine-collecting tube called a tubule which removes waste and sends minerals back to the bloodstream.


Your health care team may talk about the amount of filtering your kidneys do as “renal function.” If you have two healthy kidneys, you have normal renal function, however some people are born with only one kidney, or donate a kidney for transplantation, and are still able to lead normal, healthy lives with one functioning kidney.


Your GFR indicates how much kidney function you have. GFR can be estimated from blood work that your doctor orders.

Stage 1: Kidney damage with normal or increased GFR (90 or above)
Kidney damage may be detected before the GFR begins to decline. In this first stage of kidney disease, the goals of treatment are to slow the progression of CKD and reduce the risk of heart and blood vessel disease.

Stage 2: Kidney damage with mild decrease in GFR (60 to 89)
When kidney function starts to decline, your health care provider will estimate the progression of your CKD and continue treatment to reduce the risk of other health problems.

Stage 3:Moderate decrease in GFR (30 to 59)
When CKD has advanced to this state, complications such as cardiovascular disease, anemia, bone problems, and malnutrition become more common. Work with your health care provider to prevent complications.

Stage 4: Severe reduction in GFR (15 to 29)
If kidney function advances to this stage, continue following the treatment for complications of CKD and learn as much as you can about the treatments for kidney failure, such as kidney dialysis and transplantation. Each treatment requires preparation.

Stage 5: Kidney Failure GFR (less than 15)

At this level of kidney function, dialysis or transplantation is needed.

In addition to tracking your GFR, blood tests can show when substances in your blood are out of balance. If phosphorus or potassium levels start to climb, a blood test will prompt your health care provider to address these issues before they affect your health.


American Association of Kidney Patients

American Diabetes Association

Association of Organ Procurement Organizations

Centers for Medicare and Medicaid Services

End-Stage Renal Disease (ESRD) Networks

International Society of Nephrology

International Society of Peritoneal Dialysis

Kidney School


National Institutes of Health

National Kidney Foundation

National Kidney Foundation of Illinois

Polycystic Kidney Research Foundation

United Network for Organ Sharing

Consult with us and take charge of your healthcare decisions with the help of our Nephrologists.