

Small spot on my ceiling, should I be concerned?
I noticed this what may look like a small leak of some sort? I feel like I saw it before and forgot about it and saw it again today. After I saw it again today I thought maybe I should ask around. For context this is in my living room on the first floor. Above are bedrooms but there is a bathroom beside the bedroom that is directly underneath this spot. The home is about 22 years old. Is this normal at some point for older homes? Should I be concerned about possible mold if it has been a while it’s been there? Please let me know your thoughts and advice thank you in advance.
Edit: the spot is not soft, hard as a rock. I also spend a lot of time in this room and have never smelt anything unpleasant.