Causes of Headaches Across Organ Systems

1. Neurological Causes

• Primary headaches: Migraine, tension-type headache, cluster headache.
• Secondary headaches: Intracranial tumors, traumatic brain injury.
• Vascular disorders: Subarachnoid hemorrhage, stroke, temporal arteritis.

2. Infectious Causes

• Meningitis, encephalitis.
• Sinusitis: Inflammation of paranasal sinuses.
• Brain abscess.

3. Ophthalmologic Causes

• Glaucoma: Increased intraocular pressure.
• Refractive errors or eye strain.

4. Ear, Nose, and Throat Causes

• Otitis media or externa.
• Sinusitis.
• Temporomandibular joint (TMJ) dysfunction.

5. Cardiovascular Causes

• Hypertensive crisis.
• Carotid or vertebral artery dissection.

6. Endocrine and Metabolic Causes

• Hypoglycemia or hyperglycemia.
• Pheochromocytoma: Excess catecholamine secretion.
• Thyroid disorders.

7. Medication or Substance-Induced

• Medication overuse headache (analgesic rebound).
• Alcohol or caffeine withdrawal.
• Nitroglycerin or phosphodiesterase inhibitors.

8. Psychiatric Causes

• Stress or anxiety-related tension headaches.
• Depression-related somatic symptoms.

9. Miscellaneous/Systemic Causes

• Dehydration.
• High-altitude sickness.
• Post-lumbar puncture headache.