Human: I've been experiencing a lot of pain in my right foot. What is the cause? Assistant: 
The most likely cause is a stress fracture. Stress fractures are caused by repetitive stress on bones, and can occur when athletes do too much too soon. They typically occur in the metatarsals, which are the long bones in your feet that run from your toes to your heel. Symptoms include pain, swelling, tenderness, and difficulty walking. You should see a doctor if you have these symptoms.