Primary Headaches are not related to an underlying disease process such as stroke, cancer, drug reactions, etc. There are three main types: Migraine, Tension, and Cluster. Secondary Headaches are caused by life-threatening and non-life-threatening underlying diseases. Secondary Headaches include infections, tumors, vascular (including aneurysm), drug-induced, or idiopathic (cause unknown).
Headaches are not the result of an aspirin shortage in the body!
A 1995 study compared neck adjustments as commonly performed by doctors of chiropractic to the drug Amitriptyline, a pill used to treat headache as well as depression. The study concluded that not only were neck adjustments an effective treatment for tension headaches, but the effects tended to last longer and decreased need for over-the-counter medication.
Remember Chiropractic First, Drugs Second, and Surgery is always the last resort.