Do these symptoms sound familiar?

The last 3 days he has been severely lightheaded (couldn't get out of bed yesterday), nauseous, loss of appetite, profusely sweating, and sometimes a headache. I couldn't find anything online to match the description. I finally got him to go to the ER which is where he is at now but I had to stay home with our daughter. Has anyone experienced this if so what was it? Or does anyone know what it could be? I'm really freaked out. Please I don't want ignorant answers like "he has the flu" because I no he doesn't. I'm just curious if anyone has an idea of what it could be?