It’s very important to wear suncreen when you’re spending time in the sun. But is it really a big deal if you skip it in the fall and winter or when you plan to be inside most of the day?
Dermatologists say that applying sunscreen only in the summer or when you plan to be at the beach or the pool is not only a mistake, but can have dire consequences, especially because UV damage is cumulative and can occur even when it’s overcast.
Here’s what they say can happen if you skip applying sunscreen on a daily basis.
Exposing your skin repeatedly to UV light, whether directly or indirectly, can eventually alter your skin’s DNA. This DNA damage can lead to mutations and eventually cause skin cancer.
“Skin cancer is the most serious consequence of unprotected UV exposure, caused by DNA mutations in skin cells,” Jeannette Graf, MD, a board-certified dermatologist and assistant clinical professor of dermatology at Mount Sinai School of Medicine, told Health. “Melanoma in particular can be fatal if not caught early.”
According to Graf, UV rays can penetrate skin cells at the cellular level and alter the DNA that tells those cells how to function. “When DNA strands are broken or mutated, the cells can’t repair themselves properly. Sometimes this leads to visible changes like wrinkles or spots, but other times, it can cause cells to grow out of control, which is how skin cancers like melanoma, basal cell carcinoma, and squamous cell carcinoma develop.”
Some of the most common signs of aging skin include wrinkles, age spots, and dryness. Continued exposure to the sun, even indirectly, can accelerate this process, making your skin look much older than it really is.
“UVA rays penetrate deep into the skin and break down collagen and elastin, leading to fine lines, sagging, and wrinkles years earlier than they would naturally appear,” said Graf.
Each little exposure adds to your lifetime “UV bank account,” added Hannah Kopelman, DO, a board-certified dermatologist and host of the podcast Derm Club. “[Your] skin has a memory. Once that bank account is full, the skin starts showing visible and medical consequences. Cumulative damage is why I tell patients daily sunscreen is non-negotiable.”
Repeatedly not wearing sunscreen can also lead to uneven melanin production, which can create changes in the skin’s color or the dark spots or “age spots.” Sun exposure overstimulates pigment cells, creating uneven tone, freckles, or stubborn dark spots (like melasma).
“These can be hard to treat once they’ve set in, and usually require in-office laser or microneedling treatments to improve the appearance.”
Each time your skin is exposed without protection, a small amount of DNA and structural damage occurs, even if you don’t get visibly burned, explained Graf. Over time, those little hits of damage accumulate, breaking down your skin’s collagen and causing permanent changes to its pigmentation and texture, she said.
The outermost layer of skin is the body’s first line of defense against UV radiation. However, repeated sun exposure can damage this protective layer, reduce its effectiveness, and even lead to scarring and other issues. In fact, repeated sun damage can cause permanent textural changes and scarring, especially if blistering from a sunburn occurs, said Graf.
“If someone gets repeated burns, it alters how their skin repairs itself,” added Kopelman. “That means wounds can’t heal poorly or leave marks.”
UV light can trigger inflammatory responses in your skin, increase your skin’s redness, dilate your blood vessels, and even weaken your skin barrier. Not only can this leave your skin swollen and irritated, but you also may find that you are more reactive to skincare products, said Graf.
Sunscreen is particularly important if you are photosensitive. People who are photosensitive experience an immune system reaction to sunlight. They may experience an itchy or burning rash, red patches, and even blisters in areas exposed to the sun.
Sun exposure worsens inflammatory conditions like rosacea, lupus, or eczema, said Kopelman.
In fact, one of the most common triggers of rosacea, which is characterized by flushing, swelling, spider veins, papules, and pustules, is exposure to sunlight. Using a sunscreen with emollient and anti‐inflammatory properties may improve barrier function, decrease redness, and reduce inflammation.
For people with lupus, avoiding the sun is also crucial. About 23% to 83% of people with the disease find that exposure to UV rays worsens their condition. Sunlight can also trigger an immune system attack, triggering symptoms like fatigue, joint pain, tingling, and numbness.
Researchers have found that UV exposure can actually harm your immune system and make it less effective. In fact, UV radiation reduces both your skin and your body’s ability to offer protection.
More specifically, sun exposure changes the way your body’s immune system works, including how it produces antigens and cytokines, which help fight diseases and infections and ward off viruses and bacteria.
The most obvious impact of not wearing sunscreen is the risk of sunburn, which most people assume only happens when you spend hours at the pool or beach. But your skin can start to burn in as little as 15 to 20 minutes, the amount of time it takes to walk your dog or go for a short run.
“Protecting your skin prevents pain, visible aging, and disease,” said Kopelman. “A sunburn today might feel minor, but it’s actually DNA damage in real time. That damage can later show up as wrinkles, spots, or even melanoma.”
Even if it’s a dreary day in the middle of winter or you plan to be in the office all day, make sure to apply sunscreen as a daily step in your skincare routine. Not only is UV damage cumulative—building on itself with each exposure—but your skin can experience this damage in just a matter of minutes.
Repeated sun exposure without protection may lead to premature aging, hyperpigmentation, and even scarring. You also put yourself at risk for sunburn, skin cancer, worsening skin conditions, and a decreased immune system.
