What is the connection between kidneys and urine?

The kidneys and urine are closely connected—urine is the end result of the kidneys doing their job. Every drop of urine your body produces is a sign that your kidneys are working to remove waste and maintain balance.

Your kidneys filter your blood around the clock. As blood flows through millions of tiny filtering units called nephrons, the kidneys remove waste products like urea and creatinine, along with excess water, salts, and toxins. What remains is a yellowish fluid known as urine.

Once formed, urine flows from the kidneys through thin tubes called ureters and collects in the bladder, where it is stored until you go to the bathroom. When your bladder is full, nerves signal your brain that it is time to release urine through the urethra.

The amount and color of urine your body produces can tell you a lot about your health. For example, dark or very small amounts of urine may suggest dehydration, while very frequent or large amounts might point to an issue with fluid balance.

Urine is about 95 percent water and 5 percent waste materials. These wastes are byproducts of everything your body does—from digesting food to using energy. Without the ability to pass them out in urine, these substances would build up and cause serious health problems.

This is why urine is more than just a waste product—it is a sign that your kidneys are doing the critical work of keeping your body clean and balanced every day.

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