Feel sick when lack of sleep

Hey everyone. I've come to see if anyone ever has the same problem. Ever since I had my daughter (shes 4 years old) lack of sleep makings me become ill. I dont mean that tired knot in your stomach that you can get sometimes, I mean like I actually picked up the flu or something. And it doesn't take much. 2 days of bad sleep can really make me feel like I picked up something. I never useto have that problem. I useto be fine on a few hours of sleep. Now if I get poor sleep or not enough I just get sick..... is this a sign of a condition I dont know about? Has this happened to anyone else?