What Is a Sunburn, Really — And What Is It Doing to Your Skin?

You fell asleep on the beach. You were play­ing bas­ket­ball out­side on a hot day and for­got to reap­ply sun­screen. Or maybe, you were tak­ing a walk around the park on a cloudy after­noon, think­ing sun­screen was unnec­es­sary. And now, your skin is prick­ling with the start of a sunburn.

Sun­burns are com­mon and they don’t just hap­pen on hot sum­mer days — ultra­vi­o­let (UV) rays from the sun that cause sun­burn can dam­age your skin in the mid­dle of win­ter or on a cloudy day. 

A sun­burn might sim­ply look like a giant red patch, but there’s a lot more going on under the skin. 

Here’s a clos­er look at the sci­ence of sun­burns — and what they actu­al­ly do to your body.

1. It’s All About the UV Rays.

Your body has melanin, which is a pig­ment that col­ors your skin and pro­tects it against the sun’s harm­ful UV rays. Peo­ple with lighter skin have less melanin, which means they have less pro­tec­tion and are more prone to sun­burn. Peo­ple with dark­er skin have more melanin and greater pro­tec­tion, but they are still sus­cep­ti­ble to burn. 

When the sun hits your skin, the UV rays dam­age skin cells. Your immune sys­tem responds by increas­ing blood flow to the area, which is what makes a sun­burn red and warm. While this is hap­pen­ing, the dam­aged skin cells release chem­i­cals that trans­mit mes­sages through­out your body. Your brain inter­prets these mes­sages as a painful burn­ing sensation. 

2. Sun­burns Can Reach Dif­fer­ent Lay­ers of the Skin — and That Makes a Difference.

Just like any oth­er burn, sun­burns can vary in sever­i­ty. Sever­i­ty is mea­sured by which lev­el of skin has been damaged.

Many sun­burns are first-degree burns, mean­ing they only affect cells in the out­er­most lay­er of the skin (epi­der­mis). These burns are red and painful, and gen­er­al­ly heal with­in a few days.

Sec­ond-degree sun­burns are more seri­ous because the dam­age has extend­ed to a deep­er lay­er of skin (der­mis) and into the nerve end­ings. This can cause swelling, blis­ter­ing, and severe red­den­ing of the skin. Sec­ond-degree sun­burns are more painful than first-degree burns, and they also take longer to heal. 

Third-degree sun­burns are the most severe, but they are very rare. These burns dam­age every lay­er of your skin, can destroy nerve end­ings, and require emer­gency care. 

3. Peel­ing is Healing.

Peel­ing skin may not look pleas­ant — and may be a bit itchy — but it’s a good thing. It’s a sign that your immune sys­tem is hard at work. Peel­ing occurs when your white blood cells attack and get rid of your dam­aged skin cells. 

Let your body get rid of peel­ing skin nat­u­ral­ly. Pick­ing at peel­ing skin or using exfo­liant can cause infec­tion and make it dif­fi­cult to heal. 

If a sun­burn has dam­aged your skin, or if you have ques­tions about pre­vent­ing sun­burn, make an appoint­ment with a Duly Health and Care der­ma­tol­o­gist.

4. Sun­burns May Be to Blame for Ear­ly Skin Aging

Wrin­kles, brown spots, and fine lines — these are all skin changes that you can expect as you get old­er. But aging isn’t the only cul­prit. Pho­toag­ing, also known as pre­ma­ture aging” or sun-dam­aged skin,” is to blame for 90% of the vis­i­ble changes to the skin. Pho­toag­ing is the ear­ly aging of your skin that’s caused by a cumu­la­tive buildup of all of the sun dam­age you’ve received through­out your life. 

Your skin con­tains elastin and col­la­gen, which are pro­teins that make skin look young and smooth. Over time, sun dam­age breaks down these pro­teins, lead­ing to sag­gy, dull, and old­er-look­ing” skin. 


Inter­est­ed in learn­ing about treat­ments for younger-look­ing skin? Read about the ser­vices at Duly Aes­thet­ics.

5. Sun­burns Cause Short-Term Damage…

When you think of the imme­di­ate after­math of a sun­burn, you prob­a­bly think about painful red skin. But there are actu­al­ly sev­er­al oth­er symp­toms, and these require med­ical attention.

Get care right away if your sun­burn is accom­pa­nied by:

  • Fever
  • Dizzi­ness or fainting
  • Rapid breath­ing
  • Clam­my or pale skin
  • Chills
  • Rash
  • Severe, painful blisters
  • Extreme thirst
  • Pain in your eyes 
  • Sen­si­tiv­i­ty to light

These may be signs of oth­er seri­ous con­di­tions, like heat exhaus­tion, dehy­dra­tion, or shock.

6. …and Long-Term Damage

The long-term effects of sun­burns don’t just affect your appear­ance. Sun­burns are a lead­ing cause of sev­er­al types of skin can­cer. They are asso­ci­at­ed with about 90% of non­melanoma skin can­cers, and may cause about 86% of all melanomas — one of the poten­tial­ly dead­liest forms of skin can­cer.

  • Sun dam­age starts from your very first burn and con­tin­ues to build over time. The more sun­burns you get dur­ing your life, the high­er your risk of devel­op­ing skin cancer.
  • Your risk of devel­op­ing melanoma more than dou­bles from just one sin­gu­lar blis­ter­ing sun­burn dur­ing your child­hood or ado­les­cent years. 
  • The more sun­burns you have, the greater your risk for skin can­cer. In fact, it takes as lit­tle as five sun­burns in your entire life to more than dou­ble your risk of melanoma.
  • If you get five or more sun­burns between the ages of 15 and 20, your risk for non­melanoma skin can­cer increas­es by 68%, and your risk for melanoma increas­es by 80%. 

You Know What the Sun is Doing. What Can YOU Do?

For­tu­nate­ly, there are ways to pro­tect your­self from sun­burns — sun­screen, hats, sun pro­tec­tive cloth­ing, and sun­glass­es can go a long way in keep­ing your skin safe. 

Sun­screen in par­tic­u­lar is one of your best bets for pre­vent­ing sun­burns. Reg­u­lar­ly using a sun­screen with a sun pro­tec­tion fac­tor (SPF) of 30 or high­er dai­ly can reduce your risk of squa­mous cell car­ci­no­ma (the sec­ond most com­mon form of skin can­cer) by 40% and your risk of melanoma by 50%. 

Just make sure you’re choos­ing the cor­rect sun­screen for your skin and fol­low­ing direc­tions care­ful­ly so you can keep your skin safe and burn-free. To get the best broad-spec­trum pro­tec­tion, decrease skin reac­tions, and be envi­ron­men­tal­ly con­scious, make sure to use a min­er­al-based sun­screen that con­tains either zinc oxide or tita­ni­um dioxide.

If you’ve expe­ri­enced sun­burns and want to under­stand the impact on your skin, includ­ing your risk of skin can­cer, sched­ule an appoint­ment with a Duly Health and Care dermatologist.

  • Ainah Tan, MD, Glen Ellyn Dermatologist

    I believe in treating each patient as if they were my family, with high-quality and well-researched care. Each patient is a unique individual that deserves personalized care, whether it is treating acne, performing cosmetic procedures, to removing skin cancer. I absolutely love getting to know my patients and aim to create a comfortable environment. We look forward to helping you look and feel great about your skin!