How is blood filtered through the kidneys

If one kidney is lost, the other kidney can enlarge and provide up to 75 per cent of the normal kidney function the work of one and a half normally functioning kidneys.

It is difficult to calculate the exact rate at which your kidneys work. The best measure of kidney function is called the glomerular filtration rate GFR. This formula uses the level of creatinine in your blood to estimate how well your kidneys are filtering waste from your blood. It can indicate if there is any kidney damage.

The higher the filtration rate, the better the kidneys are working. If your doctor orders a blood test to learn more about your kidney function, an eGFR result is provided automatically, along with your creatinine results.

Your doctor may also test for other signs and conditions that may indicate you have chronic kidney disease.

These may include tests for:. Well-functioning kidneys are essential to your overall health. Early detection of kidney disease can be life-saving. Medication and changes to lifestyle, along with an early referral to a kidney specialist, can prevent or delay kidney failure. If you are at increased risk of chronic kidney disease , talk to your doctor about having a regular kidney health check.

This page has been produced in consultation with and approved by:. Bedwetting is a problem for many children and punishing them for it will only add to their distress. Approximately two quarts are eliminated from the body in the form of urine, while the remainder, about quarts, is retained in the body. The urine we excrete has been stored in the bladder for approximately one to eight hours. If you would like more information, please contact us. All rights reserved.

This material does not constitute medical advice. Each of the nephrons contain a filter called the glomerulus pronounced: gluh-MER-yuh-lus. The fluid that is filtered out from the blood then travels down a tiny tube-like structure called a tubule pronounced: TOO-byool. The tubule adjusts the level of salts, water, and wastes that will leave the body in the urine. Filtered blood leaves the kidney through the renal vein and flows back to the heart.

Pee leaves the kidneys and travels through the ureters to the bladder. The bladder expands as it fills. When the bladder is full, nerve endings in its wall send messages to the brain. When a person needs to pee, the bladder walls tighten and a ring-like muscle that guards the exit from the bladder to the urethra, called the sphincter pronounced: SFINK-tur , relaxes. This lets pee go into the urethra and out of the body. Reviewed by: Larissa Hirsch, MD. Larger text size Large text size Regular text size.

One of the main jobs of the kidneys is to filter the waste out of the blood. How does the waste get in your blood? Well, your blood delivers nutrients to your body. Chemical reactions in the cells of your body break down the nutrients. Some of the waste is the result of these chemical reactions. Some is just stuff your body doesn't need because it already has enough. The waste has to go somewhere; this is where the kidneys come in. First, blood is carried into the kidneys by the renal artery anything in the body related to the kidneys is called "renal".

The kidneys filter that blood about 40 times a day! More than 1 million tiny filters inside the kidneys remove the waste. These filters, called nephrons say: NEH-fronz , are so small you can see them only with a high-powered microscope.

The waste that is collected combines with water which is also filtered out of the kidneys to make urine pee. As each kidney makes urine, the urine slides down a long tube called the ureter say: yu-REE-ter and collects in the bladder, a storage sac that holds the pee.