Twelve-year-old Tomas Remeikis was diagnosed with pulmonary hypertension after doctors found a hole in his heart as a toddler.
The National Health Service (NHS) considers pulmonary hypertension a serious condition that can damage the right side of the heart. It causes high blood pressure in the blood vessels that supply the lungs.
Despite his diagnosis, the 12-year-old had been leading a healthy lifestyle for many years, including biking to school every day and participating in taekwondo classes twice a week. However, on May 26, Tomas, a resident of Southport, North Carolina, USA, fell ill at home.