What Is Urine Made Of?

Urine is more than just a waste product—it is a useful sign of how your body is working. Formed by the kidneys, urine helps remove unwanted substances from the blood and keeps your internal balance in check.

Urine is made up of about 95 percent water. The remaining 5 percent includes a mix of waste products, excess minerals, and other substances the body no longer needs. One of the main waste products found in urine is urea, which is created when your body breaks down proteins. Another is creatinine, a byproduct of muscle activity.

You will also find electrolytes in urine, such as sodium, potassium, chloride, and calcium. These minerals play important roles in nerve and muscle function, blood pressure regulation, and fluid balance. The kidneys control how much of each is released in the urine depending on what the body needs at the time.

Other compounds found in urine include ammonia, uric acid, and small amounts of hormones, vitamins, and enzymes. The exact makeup of urine can change throughout the day depending on what you eat and drink, how much you exercise, and your overall health.

The color, smell, and volume of urine can all give clues about hydration and kidney function. Clear or light-yellow urine usually means you are well hydrated. Dark yellow or very concentrated urine may be a sign that you need more fluids.

Urine might seem simple, but it tells a detailed story about how your body is managing waste, water, and chemical balance. That is why doctors often use urine tests to detect early signs of health issues.

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