What is the largest organ in the human body?

The largest organ in the human body is skin. It serves as a critical barrier between the internal organs and the external environment, playing a key role in protecting the body from pathogens, regulating temperature, and enabling the sensation of touch, heat, and cold. The skin is composed of multiple layers, primarily the epidermis and dermis, which contribute to its overall function and size.

While the brain, liver, and heart are essential organs with vital functions, they do not surpass the skin in terms of size. The brain is the control center for the body, the liver aids in detoxification and metabolism, and the heart is crucial for pumping blood. However, none of these organs match the extensive surface area and weight of the skin, which can cover about 22 square feet in an average adult. This significant role and coverage make skin the largest organ in the human body.