neck trouble-prove a relation beetwen the accident and nec-pain

During my work one year ago i've accident  at work. It wasn't a serious and complicated, but his effects I have seen few months  later. I've problem with my neck, I've still neck-pain. The accident has relation with my problem and  neck pain. After the event I went to home
without telling anyone they were hurt, because the accident happened towards the end of the shift.I become aware of that if no one knows that I was injured then it is going to be very difficult to make a claim for compensation later on. At present I undergo treatment. How can I prove  a relation beetwen the accident and my troubles.