As its name describes, flat foot (also known as posterior tibial tendon dysfunction or PTTD) is when the arches of your feet are very low. This can cause pain when standing for long periods of time and can even make your feet tire easily. Cavus foot is the exact opposite of flat foot. It's a condition where the arches of your feet are higher than normal. It's also known as high foot arches, subtle cavus foot or pes cavus. Like flat foot, high arches can cause a number of issues, including pain when standing or walking. It's one of the major culprits behind arch pain.

Normally individuals with cavus foot are born with the condition. Flat foot may be hereditary, or it can be acquired as an adult. Adult-acquired flat foot is usually a result of overuse or injury to the posterior tibial tendon, which is a structure that helps form the arch of the foot. However, flat foot can also be an effect of obesity, diabetes or hypertension.

If you suspect you have high arches or flat foot, consult your doctor to determine if you need treatment. Some patients do not experience pain, so treatment may not be necessary. However, if you have pain in your feet or lower back, your doctor may suggest shoe insoles or orthotics.