My heals always hurt after i sit for a while but today my left heal has not stopped hurting. it has been getting worse all day. what could cause that?

Plantar fasciitis: One of the more common causes of heel pain is plantar fasciitis which is described as sharp pain upon standing that is relieved w/further activity. Xrays can show a bone spur but it's controversial as to cause & effect. Regular stretching can alleviate this pain. Check out http://www.Mayoclinic.Com/health/plantar-fasciitis/ds00508. Go see your family doc for diagnosis & treatment.

Heel Pain: Heel pain is a common symptom for many adults, particularly those who jog, run or are otherwise physically active often. Although heel pain may be caused by a wide variety of factors, it is commonly a symptom of a greater condition, including a bone fracture or strained muscle, so it is important to talk to your physician if you experience pain in your heel.