Hi dear
Greetings to you. Hope you will be fine by the grace of Allah almighty. I'm fine too Alhamdulilah. GOD bless you dear. Yes it's right that pain is not a disease but it's a symptom. It the way of our body that something is going wrong in the body. The musculoskeletal pain is the pain of the muscles bones joints tendons and ligaments but the systemic pain is related to systems.
Best of luck for contest wishing you success.
Best regards @jannat12