Macbook Pro mid-2012 Slow, and laggy

Question

My Macbook has been running slow, and laggy aswell. I don't know whats wrong with it. I took my Macbook to the store where I bought it to see if they could fix it. After 4 days in the warehouse I came to take it back, and they said that we didn't find anything wrong with the hardware, but something with the software. They said that I had to reinstall it, but they couldn't cuz it was not included in the insurance. When I came back home, I did a backup, erased everything, and did a fresh install of Mavericks(took 1 day cuz it was slow and laggy). When My macbook reinstalled the problem was still there. It was much better before the reinstallation, but still a little slow. I also ran disc utility but it affect the problem. I also have another probelm is when I put my macook in sleep, I close the lid and then it gets hot, like if I'm playing a game or something which I don't. The light is turned off when I'm using my mac, it gets a little dim when I put my Mac to sleep with the lid open. When I close the lid the light gets bright and it shows the pulse like pattern at random points. I had to turn my mac off cuz I take it to school, and when I take it out from my bag its hot like a fry pan. The overheat also affects my battery life time in a high degree. I had 80% when I closed the lid and put it in my bag, and it got 22% when I took it out. I also did some search up with no luck so I hope you guys can help me, please, any help would be greatly appreciated and thanks in advance

Answer 1

Shazo46 wrote:
What about the problem when I close the lid it starts getting hot, like the processor is
I was referring to this link that I posted earlier:
http://www.thesafemac.com/mpg/
What about the problem when I close the lid it starts getting hot, like the processor is working at its limits???
Run an Apple Hardware Test,  that may develop a clue:
http://support.apple.com/kb/ht1509
Also what about the caches, because it was written that it can slow down mac's performance if they are corrupted, and I don't know if the are corrputed.
One eliminates that as a possibility by cleaning them. A Safe boot will do that.  Also look in the 'Safe Mac' link, the last entry titled "Clear Caches".
Ciao.