Science
How does sunburn work?
Sunburn works as your skin's damage response to too much ultraviolet (UV) light from the Sun. UV rays harm the DNA in your skin cells, so the body rushes blood to the area and triggers inflammation — the redness, heat, and pain of a burn.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how sunburn works.
Step by step
- 1Ultraviolet (UV) rays from the Sun penetrate the skin.
- 2They damage the DNA inside skin cells.
- 3The body responds with inflammation — redness, warmth, and pain.
- 4Damaged cells may peel away as the skin repairs itself.
- 5Repeated sunburn raises the long-term risk of skin cancer.
Frequently asked questions
- What actually causes sunburn?
- Ultraviolet light damages the DNA in your skin cells, triggering an inflammatory response that brings the redness, heat, and soreness.
- Why does sunburned skin peel?
- The body sheds badly damaged cells to replace them with healthy ones, which shows up as peeling a few days later.
- Does sunburn increase cancer risk?
- Yes — repeated UV damage to skin-cell DNA accumulates over time, raising the risk of skin cancers including melanoma.