I'm sorry if this isn't allowed, I know this is a picture place primarily but, I have a question

So, last night, my neutered, 5 year old boy cat just started howling and acting weird. I have 0 idea why. Other than, maybe he saw/smelled another cat last night that set him off? Idk. Has anyone else had this kind of a problem? Should I take him to a vet? He doesn’t seem to have a problem with me touching him anywhere but he’s definitely on edge and being weird/howling. He’s never done anything like this before. Thoughts?

Edit: I have taken him to a vet. We’ll see. Thanks everyone.

Edit 2: urinary blockage. Removing that and getting X-rays. Thanks everyone. Going to be an expensive visit I think.