My heel foot is in sever pain what could it be?

Depends: If on the bottom of the heel you could have plantar fasciitis. This responds to stretching, deep massage (rolling cold coke bottle or golf ball into area of most severe pain). If in the back of the ankle along the heel chord (achilles), you could have an inflamed tendon which can preceed a rupture. If that is the case you need to rest and avoid aggravation or see specialist if pain continues.

Plantar fasciitis: If the pain is on the bottom of the heel, it's likely plantar fasciitis, inflammation of the arch ligament. Ice, stretching and antiinflammatories help, but the ligament is inflamed for a reason. Wear supportive shoes, even at home. Also, make an appointment with a podiatrist who can make custom inserts for long term support.

HEEL PAIN: Heel pain has many causes. Is your pain worse first thing in the morning or after periods of rest? Is it on the bottom or back of the heel? Plantar fascitis is the most common cause of pain on the bottom of the heel. Start by doing calf stretches, ibuprofen, and wearing arch supports (all day long). If that doesn't work see a foot specialist.