As mentioned earlier, I guess everyone is different. For me it's headache + not feeling good. It's not so much about tired but it's mainly just headache for me which affects the whole body mainly the head, nose and neck area. 'Blank out' is going to sleep or taking a nap I presume. Sometimes when I have headaches due to lack of sleep, I am not able to take a nap and will need to endure right until the end of the day, and when it's time to sleep, I will surely have a longer sleep, usually going to bed early sometimes 9.30pm already sleeping and then waking up earlier.