Differential Diagnosis for Headache

• Single most likely diagnosis
  • Tension headache: This is the most common type of headache and is often described as a band or a squeezing sensation around the forehead, usually accompanied by muscle tension in the neck and scalp. It's likely due to its high prevalence in the general population.
• Other Likely diagnoses
  • Migraine: Characterized by severe, unilateral, throbbing headaches, often accompanied by nausea, vomiting, and sensitivity to light and sound. Its likelihood is due to its relatively high prevalence and the distinctive symptoms that patients often report.
  • Sinus headache: Caused by inflammation or infection of the sinuses, leading to pain and pressure in the face and head. This diagnosis is likely in patients with a history of sinusitis or allergies.
  • Cluster headache: Known for severe, unilateral orbital or periorbital pain, often accompanied by autonomic symptoms like nasal congestion or lacrimation. Although less common than tension or migraine headaches, its distinctive presentation makes it a likely consideration in certain clinical scenarios.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
  • Subarachnoid hemorrhage: A life-threatening condition caused by bleeding into the space surrounding the brain, often presenting with a sudden, severe headache (often described as "the worst headache of my life"). Early diagnosis is crucial for survival and outcomes.
  • Meningitis: Inflammation of the protective membranes covering the brain and spinal cord, which can be life-threatening if not treated promptly. Symptoms include headache, fever, and stiff neck.
  • Temporal arteritis: Inflammation of the blood vessels in the head, which can lead to blindness if not treated. It typically presents with headache, scalp tenderness, and jaw claudication in individuals over 50 years old.
  • Brain tumor: Although rare, a brain tumor can cause headaches, especially if it increases intracranial pressure. The headache is often worse in the morning and may be accompanied by vomiting and neurological deficits.
• Rare diagnoses
  • Trigeminal neuralgia: A chronic pain condition that affects the trigeminal nerve, causing intense shock-like or stabbing pain in parts of the face.
  • Hypnic headache: A rare headache disorder that occurs only during sleep and wakes the patient up, typically occurring in older adults.
  • Thunderclap headache: An extremely severe headache that reaches its maximum intensity within a minute, often indicative of a subarachnoid hemorrhage but can have other causes as well.
  • Idiopathic intracranial hypertension (IIH): A condition characterized by increased pressure within the skull without any apparent cause, leading to headaches, vision changes, and tinnitus, often in obese women of childbearing age.