Leg pain in left calf? Help?

My boyfriends left calf is going through constant severe pain to the point where he cant stand for long periods of time or touch or keep balance on it for too long. On a scale of one to ten on a normal day its a ten, and on a bad day its a 12. He's been to the doctor, and they have told him his leg is healthy with no signs of tissue damage. However, he has some of the symptoms of diabetes, and arthritis, but he does now have the actual disease. His pain will no subside. I am wondering if there are other people who have or has this condition and if there is a solution, rather than having to go to a specialist since it is expensive in the states. No relievers like leg straighteners or soaking the leg in warm water helps. Painkillers don't work either.