Over time, wearing high heels can shorten the muscles in your calves and in your back, leading to pain and muscle spasms. "Any time you wear shoes that restrict the natural shape of your foot, you’re at risk for experiencing pain," Dr. Nevins points out. According to Dr. Nevins, many women who wear high heels often suffer a shortening of the Achilles tendon because once the heel is pointed upwards, it tightens up. Stretching it again or switching to flats can be very painful; it can even lead to plantar fasciitis. "This tendon is designed to be flexible, so the foot can lie flat or point. With repetitive wear, you can develop unhealthy patterns that can persist even when you’re not wearing high heels," adds Dr. Nevins.