Chronic migraines. Mine don't affect my life too badly, luckily, because mine aren't as bad as many people's are. I know some people are completely shut down by theirs.
Generally mine start in the back of my neck and I can tell when one is coming because my visual field of view shrinks and I nauseous. Typically after they make their way up the back of my neck, they are the worst on the right side of my head. I can feel the blood in my head pound and pound, and any sort of sound that isn't deep in nature will cause pain. Light definitely also causes pain, so I try to sleep them off. It causes me to sleep upwards of 16 hours on days that I can, because there is simply nothing worth getting out of bed to do when the smallest stimuli send spikes in your heard.
If I have one and I'm unfortunately not home, the only thing remotely possible to do to try and alleviate them is to drink water, and hope that you don't have any sort of interaction. I always feel stupid when I have migraines - almost like they impede my ability to think coherently.
The things about migraines that bother me the most are how they interrupt my hobby. I enjoy gaming, but the eye strain is hard for normal people, let alone people with migraines or other similar issues. To combat them on that side of thing, I've really just tried to form better habits while on the computer. When I was younger I would leave my room dark, and now I leave all the lights on. I have the monitor set as far as it can go in my space back. I also drink at least 96oz of water a day, being even remotely hydrated is very bad for mental health.
When they do manage to definitely get in the way of typical day to day activities beyond their normal issues, it's when I do anything remotely physical. When I get my migraines and do anything (could simply be walking, which otherwise wouldn't bother me) my head throbs with higher intensity than any other time. It gets to the point where it feels like the pressure will cause my eyes to pop out, and I can feel the blood in my neck travel all throughout my head and back out. It's surreal.