Sunshine has real benefits. It helps your body make vitamin D, can boost your mood and even supports better sleep. But the same ultraviolet (UV) rays that provide these perks can also hurt your health if you get too much.

Sunburns can speed skin aging and increase the risk of skin cancer. Research suggests that even a few bad sunburns during childhood and adolescence can significantly increase a person’s risk of developing melanoma, the most dangerous type of skin cancer, later in life. And trips to the tanning salon in your younger adult years? That can raise melanoma risk by 75 percent.

Even the mildest sunburn can cause damage on the cellular level, says Dr. Maral Kibarian Skelsey, director of the Dermatologic Surgery Center of Washington. And you may not realize it until years later. In fact, says Dr. Elizabeth Hale, a Mohs surgeon and senior vice president of the Skin Cancer Foundation, it can take about 15 to 20 years for the damage to show up, sometimes in the form of cancer.

The average age for a melanoma diagnosis is 66, according to the American Cancer Society; by age 70, at least 1 in 5 Americans will develop skin cancer.

Here’s what to know about protecting your skin as you age — and what to watch for after 50 if you spent time in the sun when you were younger.

How the sun can damage your skin

Ever wonder what happens in the body when you get a sunburn? Dr. Susan C. Taylor, a leader in treating skin of color and founder of the Skin of Color Society, explains that UV light (from the sun or a tanning bed) penetrates directly into skin cells and damages the DNA, or genetic material, inside them. When the damage is too great, those cells die, which is why burned skin later peels — that’s the damaged cells flaking off.

People with darker skin tones have more natural defense against UV damage than those with lighter skin because melanin — the pigment that gives skin its color — helps absorb and disperse some ultraviolet radiation before it can damage DNA. But that added defense is not immunity, experts stress, and it doesn’t replace the need for sunscreen and other sun-protection measures.

Once the skin is injured, the body quickly shifts into repair mode, explains Dr. Adewole Adamson, a board-certified dermatologist and researcher at the University of Texas at Austin.

“Your body reacts by saying, Oh my goodness, we need to repair this,” Adamson says. Blood vessels widen, immune cells rush in and you feel heat, swelling and tenderness.

A severe sunburn can do more than leave skin red and sore. Blistering burns may trigger fever, chills, headaches, nausea and dehydration — symptoms sometimes referred to as sun poisoning. In extreme cases, the body’s response to prolonged heat and UV exposure can contribute to heat exhaustion or heatstroke.

It’s not just skin that can get damaged; the eyes are vulnerable too.

The World Health Organization estimates that 15 million people are blind due to cataracts, and of these, about 10 percent may be due to UV radiation. Higher lifetime exposure has also been linked to early age-related macular degeneration, and photokeratitis — essentially a sunburn on the cornea — can cause temporary vision loss, although this is rare. And skin cancers can occur on the eyelid.  “It’s important for people to know that there is no good sunburn,” Skelsey says.