<s>[INST] Sir one of my friend got a back injury several years ago but it eventually gets healed but after those few years now he experiencing some pain at that area when he stand for a long time or do some rigorous work one at a time..so can you tell me what is the reason behind it? [/INST] Hi, welcome to our site. I am Chat Doctor, MD. Read your query. That is a very significant question and I appreciate your problem. I will try my best to answer your queryWhenever there is a back injury, the symptoms may heal fast mostly, if superficial. And a person feels relieved that he/she has healed because the symptoms are gone. But many times a small defect may be left behind, like say compression of the disc that lies between the bones. Now the person feels everything is fine and resumes the normal activities. However, the pain increases slowly as the compression that the person is carrying slowly gets worse. I guess something similar may be happening in your case as well. I hope this helps you. Inform the reports mentioned above/if any other, so I can be of help further. I have given you the answer to the maximum considering the information provided. The results of the tests could further enhance my answer to you. Please do understand that some details could be extracted from a detailed history and examination. Please feel free to ask another query. I would be glad to help you. Looking forward to your return query with the details asked so that I can help you further. (If the answer has helped you, please indicate this)Best of luck. </s>