How Long You Can Expect a Sunburn to Last—and How To Treat It

Whether you forgot to apply sunscreen before spending the day outdoors or didn't reapply the SPF often enough during a day at the beach, you might end up with a sunburn. How long will your sunburn last—and when will the redness, pain, blistering, and peeling finally subside? Here's everything you need to know, plus sunburn warning signs that require medical attention.

What Is a Sunburn, Exactly?

"A sunburn, like a suntan, is the body's defense mechanism against harmful ultraviolet (UV) sun rays," New York City dermatologist Debra Jaliman, MD, told Health.

When skin is exposed to UV light, the body produces melanin, a dark pigment made by skin cells called melanocytes. Melanin is designed to protect the skin, and how much a person produces depends on genetics, according to the Skin Cancer Foundation.

When people who produce less melanin are overexposed to UV rays, it causes damage to the DNA in the upper layers of skin cells—resulting in a radiation burn, known as sunburn.

Not everybody responds in the same way to sun exposure. In general, people with lighter skin, freckles, or naturally red or blonde hair are more susceptible to severe sunburn, according to the American Cancer Society. But all skin types are vulnerable to UV damage, which occurs whether a person's skin gets tanned or sunburned. The damage can occur on very sunny days as well as overcast days because UV light penetrates cloud coverage.

How Long Does a Sunburn Last?

How long a sunburn lasts depends on how severe the burn is, Connecticut-based dermatologist Rhonda Q. Klein, MD, told Health. "Most sunburns will lose their associated pain and red tone in three to five days. But if you have a more severe, blistering burn, this could last up to 10 days," Dr. Klein said.

Pain from a sunburn usually starts within two to six hours of sun overexposure and peaks at about 24 hours. If you have a more serious sunburn, the skin may blister and peel. Blisters typically show up between six and 24 hours after exposure to the sun, but sometimes it takes longer for them to appear.

Peeling of the skin is part of the healing process after a sunburn, and it tends to start after about three days. It should stop when the skin is fully healed, which can take several weeks in cases of severe sunburn. While the peeling occurs, resist the temptation to pick at it, which can cause further damage, Dr. Jaliman said.

Sunburn Symptoms to Watch For

Sunburn symptoms vary depending on the severity of the damage and your skin tone. Your skin may turn red, especially if you have a fair or light-colored skin complexion. If you have a darker skin complexion, you may not notice a change in color, but your skin will still be tender.

• If you have a mild sunburn, your skin will be painful to the touch.
• A moderate sunburn may also result in some swelling, and the skin may be hot to the touch.
• A severe sunburn typically has painful blistering and, depending on your skin tone, extreme redness. Severe sunburns can be so bad they require medical attention.

Call a healthcare provider right away if you develop a fever along with your sunburn, Dr. Jaliman advised. In severe cases, too much UV exposure may lead to shock, dehydration, or heat exhaustion. Signs of heat exhaustion include:

• Extreme thirst
• Extreme pain
• Confusion
• Chills
• Rapid pulse

Blisters that cover a large surface area may also require medical care. Be alert for signs of infection in the blisters (pus, swelling, and/or tenderness).

How To Treat Sunburn

If you get burned, take quick action to try to prevent peeling:

• Cool your skin with cold compresses or take a cool shower or bath.
• Moisturize your skin while it's still damp to help lock in moisture.
• Take a non-steroidal anti-inflammatory drug—like ibuprofen, naproxen, or aspirin—to reduce pain and inflammation, if it is safe for you to take these medications.

It is best to avoid using petroleum- or oil-based ointments because they can trap in heat and make the burn worse, according to the Skin Cancer Foundation.

Scaly skin due to a peeling sunburn might not seem like a good thing at the time, but it's actually how the body gets rid of the UV-damaged cells, explained Steven Wang, MD, director of dermatologic oncology and dermatologic surgery at Hoag Family Cancer Institute in Irvine, California.

"As a reaction to the massive UV assault, the cells commit suicide as a way to prevent those with an excessive amount of DNA mutation from propagating," Dr. Wang said. Unfortunately, this process isn't perfect, and some of the surviving cells stick around and cause further mutations that could eventually become cancerous.

A single blistering sunburn in childhood or adolescence more than doubles your risk of developing potentially deadly melanoma later in life, so preventing sunburn in the first place is key.

How Can You Soothe a Sunburn and Make It Heal Faster?

Once you realize you have a sunburn, Dr. Jaliman recommended applying soothing aloe and hydrating shea butter as the moisturizer. Make sure the aloe comes directly from the plant or is fragrance-free, to avoid aggravating the skin. If you have itching and inflammation, Dr. Jaliman advised using over-the-counter hydrocortisone cream, which may also help reduce any swelling.

To speed the healing of peeling skin, Dr. Jaliman recommended holding a cold compress against your skin to cool it down and applying moisturizer regularly for constant hydration. "This will help with the skin that is peeling and the skin that is trying to heal itself," Dr. Jaliman said. Don't use an exfoliator until your skin has completely healed. The damaged skin will shed by itself, and the new skin is delicate and susceptible to irritation.

"Sunburn dehydrates you, so it's important to drink plenty of water," Dr. Klein said. "Hydrated skin will recover more quickly." Dr. Klein also suggested taking a bath with colloidal oatmeal, an anti-inflammatory that offers relief from burning and itchiness. Always stay out of the sun until your skin is fully healed or you could find yourself back with even worse sunburn symptoms.

How To Prevent Sunburn

Whether it's a full day out in the sun or day-to-day sun exposure, it's important to protect your skin. The American Cancer Society recommends these steps to minimize daily sun exposure and prevent sunburn:

• Wear a long sleeve shirt, pants, and hat when possible (UV-protective clothing is even better).
• Wear sunglasses.
• Apply a broad-spectrum sunscreen with an SPF of 30 or higher and apply it frequently.
• When possible find shade between 10 a.m. and 4 p.m. (during the strongest UV light).

A Quick Review

In the ideal situation, you want to avoid getting a sunburn in the first place. But if it happens, treat the sunburn with cold compresses and moisturizer, and drink plenty of fluids. Then in the future, prevent sunburns by covering your body with clothing, wearing sunglasses, applying sunscreen regularly to any exposed skin, and seeking shade when possible.