A young Australian woman prone to headaches had one that lasted over a week, and was accompanied by blurred vision.
An MRI and subsequent brain surgery revealed the alarming and nauseating reason for her aching head.
According to CNN, the pain was caused by neurocysticercosis: tapeworm larvae that had taken up space in her brain.
The CDC says people contract the parasitic infection by swallowing eggs found in the feces of a person who has an intestinal tapeworm.