Is updating Lightroom to latest version the same as reinstalling it?

I get terrible performance from LR.  I keep it updated.  If I don't use it for a few days, it's speed is reasonable, but after a short session in Develop, especially using healing brush, it starts to slow down, gets very slow, then freezes.  I try the usual restarts of LR and the Mac OS 10.9 computer, optimizing catalog, repairing disk permissions, but nothing helps.  Strangely, after I give up and shut everything down, if I open LR back up to start fresh, the slow, slow condition is still there, and can last for a day or so.  Then it slowly goes back to normal.  It happens with tools other than healing brush, too.   (This happens with Photoshop, too.)

An "expert" advised me to reinstall LR (and PS). 

My question: when I update LR or PS using the Creative Cloud, is that the same as reinstalling them?

If it's not the same, how do I reinstall?

By the way, is my slowdown problem common?  If so, are there known solutions?

MacPro 2009,  OSX 10.9.5,  16 gig Ram,  Nvidia Geforce GT120 (LR does not use the GPU. I think it's too old)

Thanks for any help.