A sunburn is skin damage from the sun's ultraviolet (UV) rays. Most sunburns cause mild pain and redness but affect only the outer layer of skin (first-degree burn). The red skin might hurt when you touch it. These sunburns are mild and can usually be treated at home.
Skin that is red and painful and that swells up and blisters may mean that deep skin layers and nerve endings have been damaged (second-degree burn). This type of sunburn is usually more painful and takes longer to heal.
Other problems that can be present along with sunburn include: