If you’ve ever worn stillettos, you know how painful they can be. Even though it’s trendy to opt for more comfortable footwear these days (thanks athleisure movement!)—we still wear heels, whether on special occasions or every day because it’s company dress code (yes, even in 2016!). But high heels can cause some serious problems for your body.

Your feet are the base of your body’s movement and posture, so high heels can affect your entire skeleton. “Wearing heels shifts your weight toward the balls of the feet, so your knees and hips go forward and your back must hyperextend backward in order to maintain balance,” says Jacqueline Sutera, podiatrist and spokesperson for the American Podiatric Medical Association.

Think of your feet like the foundation of a house, says Adam Kelonsky, a podiatrist at the NYU Langone Medical Center. “If two houses are built side by side, one with a level foundation and the other with uneven foundation, they’ll look identical at first,” he says. “As time goes by, the house on the uneven foundation will start to get some cracks and warping. Eventually the doors may not close properly.” Yikes.

How Heels Can Affect Your Body

1. Feet

“At the most simple level, heels don’t allow your foot to function properly,” Kelonsky says. Wearing heels can lead to joint disease in your foot bones, hammertoe deformities, calluses, bunions, ingrown toenails, neuroma—just about any foot issue you can imagine, he says.

2. Achilles Tendon

Wearing high heels on a daily basis can actually shorten and stiffen the muscle-tendon unit that connects your ankle to your calf muscle.On muscle, tendon and high heels. Csapo R, Maganaris CN, Seynnes OR. The Journal of experimental biology, 2010, Oct.;213(Pt 15):1477-9145. This can make it difficult to extend your legs and walk even when you don’t have shoes on, says Suzanne Levine, a New York City-based podiatrist.

3. Knees

Because wearing heels shifts your weight toward the ball of your foot, your knees have to move forward to keep you balanced, putting extra stress on them.Kinetics of high-heeled gait. Esenyel M, Walsh K, Walden JG. Journal of the American Podiatric Medical Association, 2003, Mar.;93(1):8750-7315.Since your joints are improperly aligned, over time you can develop arthritis in your knees (a.k.a. osteoarthritis), which could require surgery if it gets really serious.Effects of high heel wear and increased weight on the knee during walking. Titchenal MR, Asay JL, Favre J. Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2014, Dec.;33(3):1554-527X. A randomized controlled trial: effect of wearing high-heeled shoes on the lower appendicular skeleton. Koussihouede F, Falola J, Fousseni E. The Pan African Medical Journal, 2015, Mar. 20: 191. (These studies looked at relatively small groups of women, so the heels and knee connection needs more research. However the podiatrists we spoke with agreed that your knees do move out of line to keep you from tottering over when you’re wearing them.)

4. Hips

Just like your knees, your hips have to move forward to compensate for the extra pressure in the balls of your feet.Kinetics of high-heeled gait. Esenyel M, Walsh K, Walden JG. Journal of the American Podiatric Medical Association, 2003, Mar.;93(1):8750-7315. Since your hips play a major part in any type of leg movement you do (walking, running, cycling), this can lead to pain outside of your hips, including your inner thighs, butt, and groin. Your hips also have control over your entire posture (think about cat-cow pose), so when they’re out of line so is your entire spine. This can even lead to neck pain, Levine says.

5. Back

Ever wonder why your butt looks so good in heels? While your hips and knees move forward to balance out the extra weight in the balls of your feet, your lower back hyperextends backward. You might look great from behind, but it can be really dangerous for your back over time, causing chronic back soreness, back spasms, and eventually arthritis, says podiatrist L. Kelsey Armstrong.The influence of high and low heeled shoes on EMG timing characteristics of the lumbar and hip extensor complex during trunk forward flexion and return task. Mika A, Clark BC, Oleksy Ł. Manual therapy, 2013, Apr.;18(6):1532-2769. The effect of walking in high- and low-heeled shoes on erector spinae activity and pelvis kinematics during gait. Mika A, Oleksy L, Mika P. American journal of physical medicine & rehabilitation / Association of Academic Physiatrists, 2012, Jun.;91(5):1537-7385.

Frequency Matters (But Not as Much as You’d Think)

These problems are more or less common, depending on how frequently you wear heels. There isn’t a hard-and-fast rule for when you’ll start to see damage, but generally people who wear high heels every day are more prone to long-term injuries than occassional wearers. (Surpise, surprise.)

Even if you don’t wear heels very often, you’re still at risk for bunions, hammertoes, and other serious foot injuries. It just may take longer—probably five to 10 years, Armstrong says. There can be variability here too, depending on how long you walk in your heels at a time (one hour versus eight hours, for example).

Just throwing on a pair once? You should still be careful. “You are less likely to have long-term damage from wearing heels for just one day, but if you aren’t strong, are overweight, or are borrowing a pair of your friend’s shoes that don’t really fit, you could see serious damage,” Sutera says.

“Damage can start a lot earlier than you think,” adds Marlene Reid, a podiatrist and former president for the American Association for Women Podiatrists.”What’s important is educating yourself on how to wear heels more effectively so you can diminish the negative effects,” she says.

4 Ways to Diminish the Damage

Before you raid your closet and throw out anything with a heel, keep in mind there are smarter ways to wear them so you don’t suffer serious health issues.

1. Wear lower heels or wedges.

As you probably guessed, higher heels are worse for your feet. Taller shoes make you shift your weight even more, which can lead to torn ligaments and stress fractures, Reid says. The American Podiatric Medical Association recommends wearing wedges or heels that are two inches or less. Wedges still aren’t great for your feet, but the platform reduces the incline, helping you balance and lessening the pressure on the ball of your foot.

2. Opt for a wider toe.

Wide as opposed to narrow-toed heels are also a better bet. A narrower shoe can cause a pinching of the nerves between the bones in the ball of your foot, or a neuroma.

3. Change the height of the heel you wear from day to day.

One tip Reid suggests for frequent wearers is to switch between different heel heights. “Wearing heels of the same height every day consistently contracts the Achilles tendon,” she says. By regularly switching, you allow the tendon to stretch.

4. Cap the time you’re walking in heels to three hours at a time.

You may have already tried this trick: Wear flats to work or an event and switch to heels when you arrive. But it’s still a good idea to pay attention to how long you’re walking in them. For strutting your stuff, a good general cutoff is to keep your heels on for no more than three hours, Reid says.