My boyfriend is sick?

My boyfriend will wake up in the morning with a huge migraine and will be extremely dizzy. Also sometimes he will get sick to his stomach when he wakes up and will vomit several times and will feel disoriented for about 3 hours after. I dont know what could be wrong with him! He has really strange hours at work he works at night sometimes till the morning and lets just say his sleep schedule is awful. He will sometimes go two days with only 4 hours of sleep. Then the next day though he will catch up and sleep all day. Could it be his sleep habits doing this? I just want to know whats wrong with him and it seems to be happening more and more lately. He just wakes up and cant move he is so dizzy and his head hurts so bad. Please help if you can. THANKS!