Laptop extremely slow to wake up from sleep mode, 5+ minutes to wake

Hi, I am new here. Hoping someone can help me out with this issue. I work in IT so am not a complete computer bonehead and am at my wits end with this. My laptop is about 4 years old, it's a toshiba. For whatever reason, it started taking 5+ minutes to wake up from sleeping. If it sleeps for an hour, it's OK.. but if you leave it sleep all night and try to wake it up in the morning, it's...