Differential Diagnosis of Headache

The differential diagnosis of headache is broad and can be categorized into primary and secondary headaches. Primary headaches are those that are not caused by an underlying condition, while secondary headaches are those that are caused by an underlying condition.

Single Most Likely Diagnosis

• Tension headache: This is the most common type of headache and is often described as a band-like pressure around the head. It is usually mild to moderate in severity and can be caused by stress, poor posture, or muscle tension.
• Migraine: This is a type of primary headache that is characterized by recurrent episodes of severe headache, often accompanied by sensitivity to light and sound, nausea, and vomiting.

Other Likely Diagnoses

• Cluster headache: This is a type of primary headache that is characterized by recurrent episodes of severe headache, often accompanied by nasal congestion and eye watering.
• Sinus headache: This is a type of secondary headache that is caused by inflammation or infection of the sinuses.
• Cervicogenic headache: This is a type of secondary headache that is caused by referred pain from the neck.

Do Not Miss (Deadly if Missed) Diagnoses

• Subarachnoid hemorrhage: This is a type of secondary headache that is caused by bleeding into the space surrounding the brain. It is a medical emergency and can be fatal if not treated promptly.
• Meningitis: This is a type of secondary headache that is caused by inflammation of the membranes surrounding the brain and spinal cord. It is a medical emergency and can be fatal if not treated promptly.
• Temporal arteritis: This is a type of secondary headache that is caused by inflammation of the blood vessels in the temples. It can lead to blindness if not treated promptly.
• Brain tumor: This is a type of secondary headache that is caused by a tumor in the brain. It can be fatal if not treated promptly.

Rare Diagnoses

• Trigeminal neuralgia: This is a type of secondary headache that is caused by inflammation of the trigeminal nerve.
• Hypnic headache: This is a type of primary headache that is characterized by recurrent episodes of headache that occur only during sleep.
• Thunderclap headache: This is a type of secondary headache that is characterized by a sudden and severe headache that reaches its maximum intensity within a minute.

The single most important question to ask when evaluating a patient with headache is: "What is the severity and onset of the headache?" This can help distinguish between primary and secondary headaches, and can also help identify potentially life-threatening conditions such as subarachnoid hemorrhage or meningitis.