Although doctors do know exactly how migraines originate, they think that platelets, disk-like particles in the blood that assist clotting, may be involved. Platelets contain serotonin, a chemical that many researcher credit with triggering migraines. They believe that when platelets stick together," says Dr. Burning. "That may minimize their release of serotonin, which might prevent a migraine." Of course, such a mechanism is still conjecture