Trying to identify the cause(s) of chronic, unrelenting headaches that plague some unfortunate patients is a challenge faced by Medical Doctors and Doctors of Chiropractic alike. There are many different types of headaches, and multiple causes.
Food triggers may be involved, in which a person gets headaches when they ingest certain foods or food additives. Stress, both biomechanical and emotional / psychological, is often part of the picture.
Now sleep apnea has emerged as a not-uncommon culprit. The mechanism is a disturbance in proportions of oxygen & carbon dioxide caused by interruptions or aberrance of breathing.
For patients whose headaches seem insoluble, appropriate professional sleep assessment studies may yield a solution.