What arthritis can involve
Arthritis covers several conditions, and osteoarthritis is the most common of them: joint pain and stiffness that build over years, worse after rest or after a day that asked too much. The joints people notice first are usually knees, hips and hands, and the effect is less about one bad moment than about the slow narrowing of what feels possible.
What makes it hard to describe is the variation. Some days are fine. A record kept across weeks shows the proportion that were not, and what tended to come before them, which is a more honest answer than whichever day happens to precede your appointment.