If you have flat feet, your feet don’t have a normal arch when you’re standing. This can cause pain when you do extensive physical activity.

The condition is referred to as pes planus, or fallen arches. It’s normal in infants and usually disappears between ages 2 and 3 years old as the ligaments and tendons in the foot and leg tighten. Having flat feet as a child is rarely serious, but it can last through adulthood.

The 2012 National Foot Health Assessment showed that 8 percent of adults in the United States ages 21 and older have flat feet. Another 4 percent have fallen arches.

In some cases, flat feet are caused by injuries or illness, creating problems with:

  • walking
  • running
  • standing for hours

Flexible flat foot

Flexible flat foot is the most common type. The arches in your feet appear only when you lift them off the ground, and your soles touch the ground fully when you place your feet on the ground.

This type starts in childhood and usually doesn’t cause pain.

Tight Achilles tendon

Your Achilles tendon connects your heel bone to your calf muscle. If it’s too tight, you might experience pain when walking and running. This condition causes the heel to lift prematurely when you’re walking or running.

Posterior tibial tendon dysfunction

This type of flat foot is acquired in adulthood when the tendon that connects your calf muscle to the inside of your ankle is injured, swollen, or torn.

If your arch doesn’t receive the support it needs, you’ll have pain on the inside of your foot and ankle, as well as on the outside of the ankle.

Depending on the cause, you might have the condition in one or both feet.

Flat feet are related to the tissues and bones in your feet and lower legs. The condition is normal in babies and toddlers because it takes time for the tendons to tighten and form an arch. In rare cases, the bones in a child’s feet become fused, causing pain.

If this tightening doesn’t occur fully, it can result in flat feet. As you age or sustain injuries, the tendons in one or both feet may become damaged. The condition is also associated with diseases such as cerebral palsy and muscular dystrophy.

You’re more likely to have flat feet if the condition runs in your family. If you’re highly athletic and physically active, your risk is higher due to the possibility of foot and ankle injuries.

Older people who are prone to falls or physical injury are also more at risk. People with diseases that affect the muscles — for example, cerebral palsy — also have an increased risk.

Other risk factors include having obesity, hypertension, and diabetes mellitus.

There’s no cause for concern if your feet are flat and you have no pain. However, if your feet ache after walking long distances or standing for many hours, flat feet may be the cause.

You may also feel pain in your lower legs and ankles. Your feet may feel stiff or numb, have calluses and possibly lean toward each other.

If you have foot pain or your feet are causing problems with walking and running, see an orthopedic surgeon, podiatrist, or your regular healthcare provider.

Diagnosing the problem requires a few tests. Your healthcare provider will look for an arch in your feet as you stand on your toes.

If an arch exists, it may not be flat feet that’s causing your foot pain. Your healthcare provider will also look for flexion in your ankle.

If you’re having difficulty flexing your foot or an arch doesn’t appear, your healthcare provider will order more tests, such as a foot X-ray or a scan to examine the bones and tendons in your feet.

Foot support

Supporting your feet is usually a first step in treating the condition.

Your healthcare provider may recommend that you wear orthotics, which are inserts that go inside your shoes to support your feet.

For children, they may prescribe special shoes or heel cups until their feet are fully formed.

Lifestyle changes

Reducing pain from flat feet may involve incorporating some changes in your daily routine.

For example, your healthcare provider may recommend a diet and exercise program to manage your weight to reduce the pressure on your feet.

They may also recommend not standing or walking for prolonged periods.

Medication

Depending on the cause of your condition, you may have sustained pain and inflammation. Your healthcare provider might prescribe medication to reduce the discomfort from these symptoms. Nonsteroidal anti-inflammatory medications can relieve swelling and pain.

Foot surgery

Surgery may be an option in more serious cases and is usually the last resort.

Your orthopedic surgeon may create an arch in your feet, repair tendons, or fuse your bones or joints.

If your Achilles tendon is too short, the surgeon can lengthen it to decrease your pain.

Some people find relief from wearing special shoes or shoe supports. Surgery is usually a last resort, but its outcome is usually positive.

Surgery complications, though rare, can include:

  • infection
  • poor ankle movement
  • improperly healing bones
  • persistent pain

Flat feet can be hereditary and hereditary causes can’t be prevented.

However, you can prevent the condition from worsening and causing excessive pain by taking precautions such as wearing shoes that fit well and providing the necessary foot support.