Differential Diagnosis for Unilateral Headache in a 53-year-old Female with Prior Gastric Bypass

• Single most likely diagnosis
  • Migraine: This is a common cause of unilateral headaches in adults, and the patient's history does not necessarily suggest a complication from the gastric bypass that would directly cause a headache. Migraines can be triggered by various factors, including hormonal changes, stress, and certain foods, which might be relevant in a post-bariatric surgery patient.
• Other Likely diagnoses
  • Tension headache: While often bilateral, tension headaches can occasionally present unilaterally and are common in the general population.
  • Cluster headache: Although less common, cluster headaches are severe, unilateral, and can occur in cyclical patterns, which might be considered given the patient's age and gender.
  • Medication overuse headache: Given the patient's history of gastric bypass, she may be on various medications or supplements, and overuse of these or other pain medications could lead to medication overuse headaches.
• Do Not Miss diagnoses
  • Subarachnoid hemorrhage or other intracranial hemorrhages: Although unlikely, these conditions are medical emergencies that require immediate attention. A sudden, severe headache (often described as "the worst headache of my life") could be indicative of a hemorrhage.
  • Temporal arteritis: This condition, which is more common in older adults, can cause unilateral headaches and is associated with significant morbidity if not promptly treated, including vision loss.
  • Cervicogenic headache: While not immediately life-threatening, missing a cervicogenic headache could lead to prolonged pain and disability. These headaches are referred from the cervical spine and can be unilateral.
• Rare diagnoses
  • Hypnic headache: A rare condition characterized by recurrent headaches that occur only during sleep and wake the patient, typically in older adults.
  • Hemicrania continua: A rare, continuous, unilateral headache that can be accompanied by autonomic symptoms, which might be considered in a patient with a history of gastric bypass if other diagnoses are ruled out.
  • Post-dural puncture headache (if the patient has had recent spinal procedures): Although less likely without recent spinal procedures, this could be a consideration if the patient has undergone any spinal interventions.

Each diagnosis is considered based on the patient's presentation and history, with an emphasis on not missing potentially life-threatening conditions. The likelihood of each diagnosis can vary based on additional patient-specific factors and the results of a thorough clinical evaluation.