Are Flat Feet Hereditary? What Causes Them

If you have flat feet and so does one of your parents, that’s not a coincidence. Genetics play a real role in flat feet, but they’re far from the only factor. Understanding what actually causes flat feet, inherited or acquired, helps explain why some people are born with them, others develop them later in life, and why the right approach differs depending on which category you fall into.

Yes, Flat Feet Can Run in Families

There’s a meaningful hereditary component to flat feet. Foot structure, including arch height, tendon and ligament laxity, and overall bone alignment, is influenced by genetics, which is why flat feet often cluster within families across generations.

If flat feet run in your family, it doesn’t guarantee you’ll have them too, but it does raise the likelihood, and if you’re a parent with flat feet, it’s part of why it’s worth keeping an eye on your child’s foot development (though as covered in our guide to flat feet in children, this is rarely something to worry about on its own).

Congenital Flat Feet: Present From Birth

Some people are simply born with a lower arch structure that persists into adulthood. This is sometimes called congenital flat feet, and it’s one of the most common forms. In many cases, this type of flat foot is completely flexible and functions perfectly normally throughout life, sometimes it’s noticed, sometimes it isn’t, and it frequently causes no problems at all.

Acquired Flat Feet: Developing Later in Life

Not all flat feet are present from birth. A significant number of adults develop flattened arches over time, through a combination of factors:

Aging. The tendons and ligaments that support the arch, particularly the posterior tibial tendon, naturally lose some elasticity and strength over time. This gradual weakening is one of the most common reasons arches that were once more defined start to flatten in mid-to-later adulthood.

Weight gain. Extra body weight increases the load the arch has to support with every step, and over time, that added stress can contribute to the arch flattening, particularly when combined with other risk factors.

Pregnancy. Hormonal changes during pregnancy temporarily loosen ligaments throughout the body, including in the feet, and the added weight further increases strain on the arch. For some, this results in a lasting change to foot shape even after pregnancy.

Injury. Trauma to the foot or ankle, particularly involving the tendons that support the arch, can result in a flatter foot structure that wasn’t present before the injury.

Prolonged standing or high-impact activity. Occupations or activities that involve long hours on hard surfaces gradually stress the arch-supporting structures, contributing to arch flattening over years of cumulative load.

Underlying conditions. Conditions like rheumatoid arthritis, diabetes, and posterior tibial tendon dysfunction can directly cause or accelerate arch collapse, and are worth ruling out with a professional if flat feet develop suddenly or are accompanied by pain or swelling.

Why the Distinction Between “Born With It” and “Developed It” Matters

If you’ve had flat feet your entire life without issue, they’re likely just your normal foot structure, and unless symptoms show up, there’s often nothing that needs to change.

If your arches have noticeably changed, flattened more than they used to, particularly if that change happened relatively quickly or came with pain, swelling, or difficulty walking, that’s a different situation. Sudden or progressive arch collapse in adulthood is worth having assessed by a podiatrist, since it can sometimes point to tendon dysfunction or another underlying issue that benefits from early treatment rather than just supportive insoles alone.

Does Knowing the Cause Change the Treatment?

For most people, not dramatically, whether your flat feet are inherited or acquired, the day-to-day management (supportive footwear, arch-supporting insoles, and addressing any pain as it arises) looks fairly similar. But the cause does matter in a couple of specific ways:

• Acquired flat feet from posterior tibial tendon dysfunction may need more targeted treatment beyond just supportive insoles, since the underlying tendon issue itself may require attention
• Flat feet linked to an underlying condition like rheumatoid arthritis benefit from managing that condition alongside any foot-specific support
• Sudden changes are more urgent to have assessed than lifelong, stable flat feet that have never caused a problem

The Bottom Line

Genetics load the dice for flat feet, but aging, weight changes, pregnancy, injury, prolonged strain, and certain health conditions can all independently cause or worsen arch flattening over time. Whether your flat feet have been with you since childhood or developed more recently, the practical next step for most people is the same: supportive footwear and proper arch support to manage symptoms, with a podiatrist visit reserved for cases involving pain, sudden change, or an underlying condition that needs its own attention.

Our flat feet insole guide covers how to match arch support to your specific situation, whether you’ve had flat feet your whole life or you’re noticing changes now.