Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Get emergency help for new leg weakness with loss of bladder or bowel control, numbness around the groin or buttocks, or severe difficulty walking.
These symptoms can indicate pressure on the spinal cord or the nerves at the base of the spine.
Seek prompt medical assessment for rapidly worsening pain, new swelling over a bone, increasing difficulty walking, or new numbness or weakness.
Sudden severe pain or inability to put weight on a limb may indicate a fracture.
Arrange a routine appointment if you have persistent unexplained bone pain, a gradually changing bone shape, increasing hat size, or hearing loss.
If you already have Paget disease, report new pain or a change in your usual symptoms rather than waiting for a scheduled review.
Every sign above is quoted from the sofidex article on Paget disease of the bone. If you are not sure, err upward — it is always reasonable to be checked.