Flat feet get treated as a diagnosis when they are usually just a description. A lot of people have low arches, always have, and go their whole lives without a symptom. If that is you, there is nothing here to fix. The situation that deserves attention is different: an arch that is flattening over time in an adult who did not used to be flat.
The distinction that matters
Flat feet you have had since childhood are, in most cases, simply your foot shape. Feet come in a range of arch heights the way people come in a range of heights. If yours are comfortable and functional, they are fine.
An arch that is collapsing in adulthood is a different story, because something is changing. The most common reason is a gradual failure of the posterior tibial tendon, which runs along the inside of the ankle and helps hold the arch up. As it stretches and weakens, the arch progressively drops. This one is worth catching early, because it tends to progress and it is far easier to manage before the foot becomes stiff.
Signs worth paying attention to
- Aching or pain along the inside of the ankle or arch, especially after standing or walking.
- An arch that looks noticeably lower than it used to, or one foot that looks flatter than the other.
- Shoes wearing down unevenly, or the foot rolling inward more than it once did.
- Difficulty rising onto your toes on one foot, or a heel that seems to drift outward when viewed from behind.
- New pain on the outside of the ankle, which can appear later as the foot's alignment shifts.
What tends to help
For symptomatic flat feet, the goal is supporting the arch so the tissues that are working overtime get some relief. Supportive shoes with a firm midsole are the foundation. Over-the-counter or custom orthotics can take meaningful load off the tendon. Calf stretching helps, because tight calves increase the load on the arch with every step. Targeted strengthening for the muscles supporting the arch is often part of the plan.
Comfortable, long-standing flat feet generally need nothing at all. Good shoes and common sense are enough. Not every variation from average is a problem to solve.
When to come in
Come in if your arch is changing, if one foot looks different from the other, or if you have persistent pain along the inside of the ankle. The reason to do it sooner rather than later is straightforward: a flexible foot has many more options than a stiff one, and the tendon problem behind adult flatfoot responds much better when it is caught early. Individual situations vary, and an examination is what sorts out which category you are in.