Finding relief from a throbbing headache by stimulating your scalp or gently pulling your hair is a common experience. This reaction is rooted in the nervous system’s architecture and its natural mechanisms for modulating pain. The relief is a direct result of activating a sensory override system that temporarily distracts the brain from the primary pain signal. This counter-stimulation involves specialized nerve endings in your scalp and the brain’s chemical reward centers.
Sensory Nerves in the Scalp
The hair on your head is a highly sensitive sensory organ. Surrounding the base of every hair follicle is a delicate network of sensory nerve endings known as the hair plexus. This plexus functions as an extremely sensitive mechanoreceptor, designed to detect movement or a light touch. When you pull your hair, these mechanoreceptors are powerfully stimulated, sending signals to the central nervous system. The scalp is also rich in nociceptors, which are specialized pain receptors, making them effective for counter-stimulation.
Interrupting Pain Signals Through Counter-Stimulation
The mechanism that explains why this strong sensory input provides relief is known as the Gate Control Theory of Pain. This theory proposes that non-painful input can effectively block the transmission of pain signals to the brain at the level of the spinal cord and brainstem. Pain signals from a headache travel along slow, small-diameter nerve fibers, primarily the C-fibers, which transmit the dull, throbbing, or longer-lasting pain.
When you pull your hair, you activate larger, faster-conducting nerve fibers, called A-beta fibers, which transmit touch and pressure sensations. These faster signals reach the “gate” in the dorsal horn of the spinal cord first. The input from the fast A-beta fibers stimulates an inhibitory interneuron, which then prevents the slower C-fiber pain signals from passing through the gate and reaching the brain for conscious perception.
By creating a new, intense sensation, you are diverting the nervous system’s attention, causing the fast, non-painful signal to override the slow, painful one. This is similar to how rubbing a stubbed toe provides temporary relief. The strong mechanical signal generated by the hair pull physically competes with and temporarily blocks the headache signal, effectively “closing the gate” to the perception of pain.
The Brain’s Chemical Reward System
The relief experienced often feels inherently “good,” which is due to the brain’s chemical response. In response to the successful reduction of a painful or stressful stimulus, the central nervous system releases natural neurochemicals. Endorphins, which are endogenous opioids, are released and bind to opioid receptors in the brain, acting as the body’s internal painkiller.
This chemical action further dampens the pain transmission and contributes to a sense of well-being. Simultaneously, the activation of the pain relief pathway triggers the release of dopamine. Dopamine is a neurotransmitter associated with the brain’s reward system, reinforcing behaviors that lead to a positive outcome. The feeling of “good” is a combination of the mechanical interruption of the pain signal and the subsequent chemical reward that reinforces the behavior.
When Does This Behavior Become Concerning
For most people, pulling hair for headache relief is an occasional, situational coping strategy that causes no harm. However, it is important to recognize when this behavior crosses the line from a simple response to a potential compulsion. If the urge to pull your hair becomes frequent, automatic, or happens outside of headache episodes, it may signal the development of a body-focused repetitive behavior (BFRB).
A more serious concern arises if the hair pulling leads to noticeable hair loss, known as alopecia, or significant skin irritation. Compulsive hair pulling, or Trichotillomania (TTM), is a psychological disorder where individuals feel an irresistible urge to pull out their hair, often resulting in visible hair loss. A situational habit that escalates may warrant a conversation with a healthcare professional.