My ram is nearly full all the time

I am ruing 16.04LTS, 4.4 generic keel, with CIamon 3 as my windows manager. My computer has been bogging down recently, I thought maybe my cpu was overloading. But it's not. I have a dual core and both cores are ruing at around 30%, with occasional spikes to around 50%. But my ram is ruing full 7.5 out of 7.8gb, constantly. . My swap file is 9.3 gbs, yet only half a gig is being used. Is there anything I can do about this or is my computer hardware getting old?