Analgesic rebound is a common cause of chronic daily headache. The "rebound" refers to the phenomenon that occurs with daily use of pain medications. Generally, if a medication is taken too frequently, a state of withdrawal can occur between the doses of medication. During the withdrawal phase, the headache becomes worse and more medication is taken, thus perpetuating the problem.

Eventually, a continuous, daily headache may develop. Any headache medication (including Tylenol) can cause rebound headache, but narcotics, ergots, and caffeine are the most notorious offenders.