Plantar fasciitis causes pain primarily on the bottom of the foot, specifically around the heel and the arch area. The pain is usually sharp or stabbing near the heel and can sometimes be accompanied by aching or burning along the sole of the foot. It is often most severe with the first steps after waking up or after periods of rest, and may worsen after prolonged standing, walking, or physical activity

. Key locations of pain include:

• The bottom of the heel (most common)
• The arch of the foot (less common but possible)
• The area where the plantar fascia ligament attaches to the heel bone

The pain typically improves with movement but can return after long periods of standing or after sitting down for a while

. In summary, plantar fasciitis hurts on the underside of the foot, mainly at the heel and sometimes extending into the arch area.