Nicole Spencer, 24, a medical student who suffers from Postural Orthostatic Tachycardia Syndrome (POTS), checks her pulse with an oximeter, while she lies on the couch at her apartment, in Syracuse, New York, U.S. May 8, 2022. Three times a day, Nicole uses the oximeter to check that her heart rate hasn't raised, as a regular part of her treatment. REUTERS/Magali Druscovich
