Differential Diagnosis for Unilateral Headache
- Single most likely diagnosis
- Migraine: This is the most common cause of unilateral headache, characterized by recurrent episodes of severe, throbbing pain, often accompanied by sensitivity to light, sound, and nausea.
- Other Likely diagnoses
- Cluster headache: Known for its severe, unilateral orbital or periorbital pain, often accompanied by autonomic symptoms like lacrimation and nasal congestion.
- Tension-type headache: Although typically bilateral, tension-type headaches can occasionally present unilaterally, characterized by a pressing or tightening sensation.
- Temporomandibular joint (TMJ) disorder: Can cause unilateral headache due to pain referral from the TMJ area.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Subarachnoid hemorrhage: A life-threatening condition that can present with a sudden, severe unilateral headache, often described as "the worst headache of my life."
- Temporal arteritis (Giant Cell Arteritis): Can cause unilateral headache, especially in older adults, and is associated with jaw claudication, visual disturbances, and polymyalgia rheumatica.
- Cervicogenic headache: Originates from the cervical spine and can refer pain unilaterally to the head, often accompanied by neck pain and limited range of motion.
- Rare diagnoses
- Hemicrania continua: A rare, continuous, unilateral headache that is typically responsive to indomethacin.
- Trigeminal neuralgia: Characterized by sudden, severe, shock-like pain in one side of the face, which can be mistaken for a unilateral headache.
- Occipital neuralgia: Involves the nerves that run from the base of the skull to the scalp and can cause unilateral headache, often described as sharp or stabbing.