Plantar fasciitis is the most common cause of heel pain. The plantar fascia is the flat band of tissue (ligament) that connects your heel bone to your toes. It supports the arch of your foot. If you strain your plantar fascia, it gets weak, swollen, and irritated (inflamed). Then your heel or the bottom of your foot hurts when you stand or walk. Plantar fasciitis is common in middle-aged people. It also occurs in younger people who are on their feet a lot. It can happen in one foot or both feet.
The major complaint of those with plantar fasciitis is pain and stiffness in the bottom of the heel, although some experience pain at the bottom mid-foot area. This develops gradually over time. It usually affects just one foot, but it can affect both feet. Some people describe the pain as dull, while others experience a sharp pain, and some feel a burning or ache on the bottom of the foot extending outward from the heel. The pain is usually worse in the morning when you take your first steps out of bed, or if you've been sitting or lying down for a while. Climbing stairs can be very difficult due to heel stiffness.