What does "cephalgia" mean and what are its types?

Cephalgia, more commonly called cephalalgia, means headache or head pain, from cephal meaning head and algia meaning pain. Primary headache types include tension-type headache presenting as bilateral pressure, migraine presenting as unilateral throbbing pain with nausea and light sensitivity, and cluster headache presenting as severe unilateral pain around the eye. Secondary headaches result from underlying conditions such as infection, trauma, vascular disorders, or increased intracranial pressure. Related terms include neuralgia meaning nerve pain and cranialgia meaning skull pain.