Short Answer
Clenching can increase chewing-muscle and temple-muscle tension, which may worsen headache.
How to think about it
Unconscious clenching creates sustained pressure on the jaw joint and chewing muscles. That tension can extend toward the temples and neck.
Evidence and limits for this question
What this question checks
This page uses the question "Why does my headache feel worse when I clench my teeth?" to organize a symptom pattern before assuming a TMJ-related cause.
What to rule out first
Urgent, organ-specific, dental, ENT, neurologic, traumatic, infectious, or breathing-related warning signs should be considered before jaw-related interpretation.
What is reviewed in clinic
Consultation details, symptom timing, jaw movement, chewing muscle tension, bite changes, previous exam results, and recurrence patterns may be reviewed together.
What not to decide from this page
Do not use this page alone to choose a diagnosis, appliance, procedure, medication, or emergency response.
Safety note
Repeated headache should not be dismissed as stress alone. Check for warning signs before connecting it to jaw function.