Lisa O’Brien fell ill just after arriving home in Utah following a Hawaiian vacation in March 2020. She was among the earliest COVID-19 cases in her state. Though she didn’t land in the hospital, she’s never really recovered. Her heart beats with wild irregularity, she’s fatigued, she’s had blood clots. And even though she once had a clockwork-like menstrual cycle, she’s had only five periods in nearly two years. She was 42 when she got sick, so the change was surprising: She’s very young to be going through menopause.

After she launched a private Facebook group in June 2020—the Utah COVID-19 Long Haulers—she realized that many others also had lingering symptoms, a phenomenon now referred to as long COVID.