There are 4 ICD-9-CM codes below 346.1 that define this diagnosis in greater detail. Do not use this code on a reimbursement claim.
Clinical Information
Recurrent unilateral pulsatile headaches, not preceded or accompanied by an aura, in attacks lasting 4-72 hours. It is characterized by pain of moderate to severe intensity; aggravated by physical activity; and associated with nausea and / or photophobia and phonophobia. (international classification of headache disorders, 2nd ed. Cephalalgia 2004: suppl 1)