What sunburn is
Sunburn is an inflammatory reaction to too much ultraviolet radiation, mainly UVB. The UV damages the DNA in skin cells, and the body responds by increasing blood flow to the area and starting repair, which causes redness, warmth and pain. Cells that are too badly damaged may be signaled to die, which is why burned skin often peels a few days later. The role of cell damage in long-term risk is touched on in the article on skin DNA.
A sunburn is a sign the skin has been injured. It is not a healthy step toward a tan.
How it develops
Redness usually appears a few hours after exposure and tends to peak somewhere between about 12 and 24 hours. Because you cannot feel UV, it is easy to get burned before you notice. Skin may feel tight, hot and tender, and may itch as it heals. After a few days, it often flakes or peels.
How easily you burn depends on your skin type, the season, the time of day, altitude, reflective surfaces and the protection you used. Many people also burn faster than they expect when sunscreen is applied thinly or not reapplied, as covered in the articles on sunscreen amount and sunscreen reapplication. Some medicines and skin products can make skin more sun-sensitive, so ask a pharmacist if you are unsure.
General care at home
For mild sunburn, care is mostly about comfort while the skin recovers. Nothing speeds up the repair of damaged cells, but these measures are commonly suggested:
- Get out of the sun. Go inside or cover the area fully until the skin heals.
- Cool the skin. A cool (not ice-cold) shower, bath or damp cloth may ease heat and pain.
- Moisturize gently. A plain, fragrance-free moisturizer can help with tightness and flaking. Gel or lotion textures often feel better than thick, heavy creams on hot skin.
- Drink fluids. A burn draws fluid toward the skin, so keep drinking water.
- Consider a pain reliever. Over-the-counter pain relievers may help some people, but follow the label and ask a pharmacist or doctor if you are unsure whether it is safe for you.
- Wear loose, soft clothing. Tight or rough fabric can irritate.
What to avoid
- Do not pop blisters. They protect the skin underneath, and breaking them raises the risk of infection.
- Do not peel flaking skin. Let it come off by itself.
- Avoid heavily perfumed lotions and products that may irritate burned skin. The reasons are covered in the article on fragrance sensitivity.
- Avoid actives like retinol products and exfoliating acids on burned skin until it has fully healed, since they can irritate it more.
- Avoid petroleum-heavy or oily products on very fresh burns, because they may trap heat. Advice varies, so a pharmacist can help you choose.
- Do not use numbing products unless a pharmacist or doctor suggests it, as some can cause reactions.
- Avoid more sun. Burned skin is more vulnerable, and it may need a week or more to settle.
Skin that is peeling or irritated is also more likely to react to products, so keep the routine very simple. The articles on the skin barrier explain why gentle care matters while skin is healing.
When to seek professional help
Many mild sunburns can be managed at home, but some need medical attention. Contact a doctor, urgent care or emergency service promptly if you or someone else has:
- Blistering over a large area, or blisters on the face, hands or genitals
- Fever, chills, nausea, headache or confusion
- Signs of dehydration such as dizziness, a very dry mouth, little urine or fainting
- Severe pain that is not helped by simple measures
- Signs of infection, such as pus, spreading redness or increasing warmth
- A sunburn on a baby, especially under one year old
- A sunburn that does not improve or seems to be getting worse after a few days
These are general warning signs, not a full list. When in doubt, ask a professional.
After a burn
Burns can leave temporary dark marks or uneven color. These marks are discussed in the explanation of hyperpigmentation. Repeated sunburns, especially in childhood, are associated with a higher chance of skin cancer later in life. Having your skin looked at if you notice a new or changing spot is a sensible habit, as covered in the article on skin checks.
The best strategy is preventing the next burn through shade, protective clothing and sunscreen. This article is general information, not medical advice.