Humans pee to get rid of waste chemicals and extra water that would otherwise build up in the body and make us sick. This process mainly happens through the kidneys, which clean the blood and make urine.
Main purpose
The primary reason for peeing is to remove toxic waste products, especially those made when the body breaks down proteins, along with other dissolved chemicals the body no longer needs. If these wastes were not removed in urine, they would accumulate in the blood and damage organs.
How the body does it
The kidneys constantly filter the blood, pulling out waste substances and some water to form urine, which then travels to the bladder through tubes called ureters. When the bladder fills and stretches, nerves signal the brain, and coordinated muscle actions let urine flow out through the urethra when a person chooses to pee.
Extra water and balance
Peeing also helps control how much water and salts (electrolytes like sodium and potassium) are in the body, which is crucial for blood pressure, nerve signals, and muscle function. When someone drinks more fluid, the kidneys usually make more, paler urine; when dehydrated, they conserve water and make smaller amounts of darker urine.
