It's totally understandable to want to have a little color, but you shouldn't lie out with the intent to get a tan that rivals the skin of the Tan Mom.
"Even if you're using an SPF of 30 or higher and reapplying properly, you'll still get a little color," Doris Day, M.D., a cosmetic dermatologist in NYC, says. "Sunscreen isn't an impenetrable formula, meaning the sun's rays can still reach your skin, causing melanin to produce and a tan to occur. But applying sunblock is necessary because you need to protect your skin from the less beautiful, incredibly harmful things that can happen to your body from being out in the sun."
So, what is actually happening when you sit in the sun? Dr. Day tells Cosmopolitan.com:
1. Your skin's DNA is getting damaged.
There are two different types of rays that reach our skin: UVB and UVA. UVB rays are shorter wavelengths of light, so they penetrate to the bottom layer of our epidermis (aka skin) called the basal layer. This layer contains small, round cells called basal cells that continually divide, allowing our skin to regenerate every 28 days. But when you're in the sun unprotected, the UVB rays hit the dividing cells and cause DNA damage. Additionally, the sun triggers melanocyte cells that stimulate melanin production (this gives your skin pigment) to rise to the top of your basal layer to protect your DNA. All you end up seeing is a tan, but what's really going on is your body is freaking out because it's being burned, so it goes into protection mode. That's why it's so important to wear SPF.
2. UVA rays break down collagen and elastic, causing premature aging.
UVA rays, which are strongest earlier and later in the day, are longer wavelengths of light that penetrate more deeply into the layers of your skin where the collagen and elastin tissue (what gives your skin structure) live. The rays cause the collagen and elastin to break down, which leaves you with less firm skin. Note: This is what you're causing when you go to a tanning bed.
3. Getting sunburn after sunburn can cause your cells to turn cancerous.
When you get sunburned, your skin goes through a repair process where it has to decide whether or not the affected cell is too damaged to stick around or not. If the cell is beyond repair, it will choose to die. If the cell is somewhat damaged and tries to repair itself, but does so unsuccessfully, it can become defected and turn into a cancerous cell. This is where the cancers basal-cell carcinoma (the most common form of cancer in the U.S.) and squamous cell carcinoma come from.
Melanoma, on the other hand, occurs when the melanocytes get damaged and divide, which they're not meant to do, when they're stimulated from too much sun.
4. The sun affects everyone's skin, light to dark, but fair-skinned people are at the greatest risk for melanoma.
If you're very fair, that means that your skin can't make the proper melanin that protects you from getting burned. So, your skin will just keep getting bombarded with UVA rays and put you at a higher risk for melanoma. That's why regardless of whether you're light, medium, or dark-skinned, it's crucial to slather on sunscreen when you're outside, since everyone is at risk of getting burned or getting skin cancer, especially if you have a family history.
5. The sun causes freckles, which is a cute way of saying "sun damage."
Basically, sun damage is a cluster of concentrated melanin that becomes more prominently visible when you've had too much sun. Another form of sun damage that shows up on your skin as large brown patches is melasma. This is common side effect of women who are taking hormones, like birth control, and are out in the sun and not using enough SPF.
6. Too much sun over time can make your young skin behave like old skin.
If you've ever looked at your grandma or grandpa—or even your mom or dad—chances are they have brown spots on their face, which is due to some melanocytes being more stimulated than others; this causes patches of pigment to crop up on their skin. But you don't have to be old to get age spots. If you're young and constantly outdoors without protection, brown spots that would otherwise show up when you're older can take real estate on your mid-twenty-year-old face and body skin. Those spots aren't cute and can only be fully taken off with a laser.
7. The sun can cause broken blood vessels.
Blood vessels that are close to the surface of your skin, but normally wouldn't be visible to the naked eye, can dilate and become visible due to the intense heat from lying out. When you're in the sun, your body tries to control its temperature, so instead of the blood vessels in your body retracting, they expand beyond the point of being able to retract in order to keep your body cool. This leaves you with thin, unsightly blood vessels usually around your nose, your cheeks, or your chest.
8. The sun's rays can make your acne worse.
Contrary to popular belief, the sun isn't healing your acne. Instead, as your face gets red from the sun, it makes any breakouts you might already have blend in, creating the appearance of clearer skin. But what's really going on is the sun causing your skin to dry out and trigger more oil production, which can lead to more zits.
9. The sun essentially boils the water out of your hair.
This means you have to work harder to keep your hair hydrated with leave-in conditioner. Otherwise, the sun will dry up all the moisture in your hair, leaving it feeling brittle and sometimes leading to breakage.
10. Not protecting your hair properly alters your hair color.
If you're not protecting your hair color with a cap, scarf, or hair spritz with UV protectant in it, your brown hair will become brassy and red, your blonde hair will get blonder, and your red hair will fade—especially if it's not your natural shade.
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.