After she got back home from the dance, Zeager continued to experience a racing heart. “I was thinking, ‘Is this how it is to have feelings?'” Zeager told Insider.

The next morning, Zeager’s “butterflies” had morphed into a deep fatigue and heaviness in her arm. Her vision narrowed, her ear flooded with warmth, and she collapsed.

“Before I knew it, I was on the floor,” Zeager said. “It felt like an elephant was on my chest.”