Plantar fasciitis is one of the most common causes of heel pain. It occurs when the plantar fascia—a thick band of tissue running along the bottom of your foot—becomes inflamed due to overuse or strain
Causes and Risk Factors:

Inflammation of the plantar fascia
Overuse of the plantar fascia
Strain on the plantar fascia
Pain in the bottom of the foot
Tight calf muscles or Achilles tendons
Symptoms:
Sharp, stabbing pain in the heel (especially in the morning or after rest)
Pain worsens after prolonged standing or walking
Tightness in the arch of the foot
Pain in the bottom of the foot
Swelling or tenderness on the bottom of the foot