A burn is when you have tissue damage, usually after contact with heat.

There are three types of burns:

First-degree burns (superficial burns) are mild compared to other burns. They cause pain and reddening of the epidermis (outer layer of the skin).
Second-degree burns (partial thickness burns) affect the epidermis and the dermis (lower layer of skin). They cause pain, redness, swelling, and blistering.
Third-degree burns (full thickness burns) go through the dermis and affect deeper tissues. They result in white or blackened, charred skin that may be numb.
Fourth-degree burns go even deeper than third-degree burns and can affect your muscles and bones. Nerve endings are also damaged or destroyed, so there’s no feeling in the burned area.