Unless you've been living in a cave for the past 30 years, you probably know that exposing your body to the sun without any protection can do long-term damage to your skin. Although your nails are made of a protein called keratin, it's important to protect them from the sun as well.
If you apply sunscreen to your hands, you're probably already covering the most vulnerable area near your nails: your cuticles and nail folds. The cuticles cover the base of your nail and protect the new growth that emerges from underneath. Cuticles are susceptible to drying out, just like other parts of your skin, and if your cuticles are too dry, it can affect the growth of your nails. The nail folds are the flaps of skin that frame the base of your nails, and they're also susceptible to sun exposure [source: Mayo Clinic].
Sun damage can cause vertical ridges in your nails, which become more common as you age [source: Grumman]. You can treat these ridges by applying a nail polish basecoat with ridge filler, but once ridges form, it'll take four to six months for the nail to grow out so the ridges are no longer visible. Toenails, on the other hand, will take a year to a year and a half to grow from cuticle to tip [source: Robb-Nicholson].
If your cuticles or nail folds are damaged, you're more likely to contract a fungal or bacterial infection -- cracked skin gives germs access to your bloodstream. Infections, especially fungal infections, can be difficult to heal, so if you notice inflammation, pain, a hardening of your nails or any other changes in how your nails look or feel, consult a doctor [source: Robb-Nicholson].
For more information on protecting your nails from the sun, check out the links on the next page.