Why would someone's feet hurt on the heels so bad?

Heel pain: Is likely the most common complaint a podiatrist sees. Likely either plantar fascitis and or heel spur. Many treatment options are available and most common complaint is pain upon getting out of bed in the morning and after rest.

Plantar fascitis: Most common cause of heel pain is from plantar fasciitis, a pull/sprain of the plantar fascia from where it attaches to the heel bone on the bottom on the foot.

Plantar fasciitis: If pain is worst when first getting up it is plantar fasciitis. See a podiatrist for treatment.