I have a 26years old boyfriend who has a problem of leg pain since when he was two and a half years. The pain attacks on him suddenly without any prior symptoms. He has never found a reason for this problem as it keeps occurring after long irregular intervals. He tells me that he has seen a number of doctors since his childhood to get rid of this sudden occurrence of excruciating problem, but all have proven to no avail. He feels this pain in anyone of his legs at a time and in the calf muscle of the leg. He doesn't have respiratory problems during this, neither does his leg turns reddish and swells up, so I believe its not a case of deep vein thrombosis. There have been several tests done but the doctors never had an answer to this problem of his. Nowadays because he has got work in sites he feels that a bit of extra work pressure initiates this problem in him. He never takes any sedatives, drugs, or pain killers to overcome the pain. So can you please suggest that what is the exact problem with him? and can pain killers be taken during the time of excruciating pain? please help.