Foot pain during pregnancy is extremely common, affecting more than half of all pregnant women by the third trimester. It happens because of a perfect storm: hormonal changes loosen the ligaments in your feet, rapid weight gain shifts your center of gravity forward, and fluid buildup puts pressure on nerves and soft tissue. Most foot pain starts in the second trimester and peaks in the third, but the causes begin working much earlier.
Hormones Loosen Your Foot Ligaments
Your body produces a hormone called relaxin during pregnancy, and its levels rise to seven to ten times their normal amount. Relaxin’s primary job is to loosen the ligaments around your pelvis to prepare for delivery, but it doesn’t target just one area. It works systemically, breaking down collagen throughout your body, including in the 30-plus joints and more than 100 ligaments in each foot.
Relaxin triggers enzymes that degrade the structural proteins holding ligaments together. When the ligaments in your feet become more elastic, the arch loses some of its support. This is why many pregnant women notice their feet flattening and spreading. The arch drop changes how your foot absorbs impact with every step, shifting stress to structures that weren’t designed to bear it, particularly the thick band of tissue along the sole known as the plantar fascia.
Weight Gain Changes How Your Feet Bear Load
As the baby grows, most of the added weight concentrates in the front of your lower torso. This pulls your center of gravity forward, which changes your posture and the way pressure distributes across the bottom of your feet. A longitudinal study tracking plantar pressure throughout pregnancy found that pressure under the big toe, the first metatarsal (the ball of your foot near the big toe), and the fifth metatarsal (the outer edge) increased significantly across all three trimesters. Heel pressure also rose, but mainly between the first and second trimesters, with little additional change after that.
This means that by late pregnancy, your forefoot is absorbing a disproportionate share of the load during walking. That maldistribution explains why the balls of your feet can ache after even short periods of standing. It also forces your foot muscles to work harder to maintain balance, which can leave them fatigued and sore by the end of the day.
Swelling Puts Pressure on Nerves and Tissue
Blood volume increases by roughly 45% during pregnancy, and plasma volume alone rises by 50% or more, most of it by 34 weeks. At the same time, the growing uterus compresses the large veins that return blood from your legs, increasing venous pressure below the waist. Lymphatic drainage slows, and the protein concentration in your blood drops, making it easier for fluid to leak out of blood vessels and into surrounding tissue. The result: lower extremity edema is nearly universal in late pregnancy.
This swelling does more than make your shoes feel tight. Fluid accumulation in the foot can compress the posterior tibial nerve as it passes through a narrow channel on the inside of your ankle called the tarsal tunnel. When that nerve gets squeezed, you may feel tingling, burning, or shooting pain along the inner ankle and sole. This is more common in the third trimester, when edema, arch drop, and vein dilation are all at their peak.
Plantar Fasciitis and Other Common Conditions
Plantar fasciitis, the sharp heel pain you feel with your first steps in the morning, is one of the most frequent foot complaints during pregnancy. The combination of loosened ligaments, a flattening arch, and increased body weight places extra tension on the plantar fascia with every step. Studies report that foot pain prevalence climbs from 13 to 47% in the first trimester to 37 to 63% in the third.
Overpronation, where your foot rolls inward too much during walking, becomes more pronounced as the arch drops. This altered gait can strain the tendons along the inner ankle, cause pain in the ball of the foot, and contribute to knee or hip discomfort that seems unrelated to your feet but originates there. Some women also develop metatarsalgia, a general aching or burning under the ball of the foot, driven by the increased forefoot pressure described earlier.
Some Foot Changes Are Permanent
Here’s something many women don’t expect: pregnancy can permanently change foot structure. Research from the University of Iowa followed women from their first trimester through about 19 weeks postpartum and found lasting decreases in arch height and arch rigidity. The ligaments that stretched under the combined effects of relaxin and increased body weight did not fully bounce back, even though relaxin levels return to normal within 48 hours of delivery and other musculoskeletal changes typically resolve within six weeks postpartum.
This is why so many women report going up half a shoe size or more after pregnancy. The foot gets slightly longer and wider as the arch flattens permanently. These changes tend to be most significant with a first pregnancy, with smaller shifts in subsequent ones.
When Swelling Signals Something Serious
Gradual swelling in both feet, especially after standing or at the end of the day, is a normal part of pregnancy. What’s not normal is sudden swelling, particularly if it appears in your face and hands at the same time. Sudden puffiness combined with a rapid jump in weight can be a sign of preeclampsia, a serious blood pressure condition that typically develops after 20 weeks. If swelling comes on quickly, is markedly worse on one side, or is accompanied by headaches or visual changes, that warrants immediate medical attention.
Practical Ways to Reduce Foot Pain
Supportive footwear makes the biggest difference. Shoes with built-in arch support and a cushioned sole help compensate for the loss of your natural arch. Avoid flat shoes like ballet flats and flip-flops, which offer no structural support and allow the arch to collapse further under load. If your current shoes feel fine but your feet still ache, an over-the-counter arch support insert can help redistribute pressure more evenly across the sole.
Compression socks in the 15 to 20 mmHg range are the most common choice during pregnancy and are available without a prescription. They help push fluid back up toward your heart and can noticeably reduce end-of-day swelling and heaviness. If you have moderate edema, existing varicose veins, or spend long hours on your feet, the 20 to 30 mmHg level (considered medical-grade) may work better. Put them on first thing in the morning before fluid has a chance to pool in your lower legs.
Elevating your feet above heart level for 15 to 20 minutes several times a day helps drain accumulated fluid. Gentle calf stretches and rolling a cold water bottle under the arch of your foot can ease plantar fascia tension. Staying active with low-impact exercise like walking or swimming supports circulation and helps manage overall weight gain, both of which reduce the load on your feet. Ice applied to sore arches or heels for 10 to 15 minutes at a time can also calm inflammation after a long day.