This is called inflammation. The inflammation occurs in the plantar fascia, which is a thin layer of tough tissue that supports the arch of the foot. The pain is usually worse when you first get out of bed. The cause is usually some combination of tightness of the foot and the calf, weakness of the foot, improper athletic training or stress on the arch of the foot. Treatment can reduce or get rid of what is causing plantar fasciitis.
Treatment can also lessen inflammation.
To decrease the stress on the plantar fascia, you may need to wear shoes with more arch support. You might even need to change the size of shoe you wear. Athletes and active people may need to spend less time doing actions that cause stress, like jogging, jumping or running. Sometimes, arch supports or special shoe inserts may be used. Stretching and strengthening exercises are also good.