The place behind the ankle bone and beneath the heel hurts when i wake up in the morning. dwindles as the day progresses. what could be the reason?

Tendonitis/fascitis?: this sounds like inflamation of the insertion of the plantar fascia in the heel area. If it is worse in the morning, that is a sign. See a doctor and have him evaluate the issue, perhaps xray. Treatment will depend on the findings but might include a night splint, exercises, and ibuprofen

Plantar fasciitis?: Hello, your symptoms sound like they could be the result of a very tight heel cord. We call this plantar fasciitis. This responds to stretching the heel cord and other conservative measures, such as using a heel cup shoe insert, rolling a frozen golf ball with your heel 15 minutes at a time, and massage. See a doctor for further diagnosis and treatment, or a referral to a podiatrist if necessary.