Is there a reason why i am getting 12+ hour long headaches in the back of my head?

Neck strain/pain?: Do you have a history of headaches? Are you having other symptoms with your headaches? (vision changes, dizziness, nausea, vomiting, fever, neck/back/leg pain, decreased coordination?) how long have your headaches been going on? Consider whether sleep position or daytime work positions might impact your head/neck consider having an evaluation with doctor or chiropractor consider meds.