had a hard time sleeping. finally fell asleep at around 2am; woke up at around 4:19am.
I've been drinking not enough water lately, maybe 3-4 cups per day. as I didn't have any headaches, i figured I could get away with it.
went to the kitchen and drank a cup of water. opened my window and started to breath in fresh air with deep breaths in and out.
headache lasted for about 10 mins until 4:29. this was either lack of water, lack of oxygen, or both. it was about a 4/10.