It has been 20 years since Zheng Changgui had a heart and lung transplant, and each day he lives, he sets a new record as the longest-living such patient in Asia.

When he was 12 years old, Zheng, who was born in a rural village in Shaoyang, Hunan province, had difficulty breathing and the skin around his mouth darkened during PE class. Two years later, he was diagnosed with congenital heart disease with a ventricular septal defect by the Second Xiangya Hospital of Central South University in Changsha, Hunan.

As he also had severe pulmonary arterial high blood pressure and Ehlers-Danlos syndrome, which meant he had fragile blood vessels, the only treatment was to have heart-lung transplant surgery.

After four years of waiting for a suitable organ donor, he had surgery at the hospital in 2003 when he was 19 years old. A total of 10 senior experts from the hospital carried out the surgery for him pro bono.

"I didn't know that I was getting a heart and lung transplant. The doctors and my parents didn't tell me so I wouldn't be so afraid," the 39-year-old said.

The surgery lasted for more than seven hours and it was a great success, he said.

He could leave his bed for simple movements after three days. In 280 days, he could do mild physical activity, and after a year, he could live like a normal person.

"What is different for me from normal people is that I have to take anti-rejection medication every day and it takes longer for me to recover from a cold or fever," he said. Early this year, he caught COVID-19 and although his symptoms were more severe than most people, he has recovered.

Two years after his surgery, the hospital offered to let him work at its library so it would be easier for him to get checkups. The hospital has also waived much of his medication and checkup fees since his surgery.

One of the biggest changes for him is that his lips have returned to their normal color and he has more stamina to exercise.

In his spare time, he often reads books, goes to parks and takes small walks. He has also taken part in the national sports competition of organ recipients to make friends with other survivors of organ transplant surgeries.

Zheng is well-known at the hospital, and all the doctors and nurses in the cardiovascular and pulmonary department know who he is.

His story has been an inspiration for other patients. Whenever patients and family members ask him for advice, he often tells them to not lose hope and to be patient.

"The key for us is to take medication every day. You can be OK if you do not eat for a day, but something bad will happen to you if you do not take drugs regularly," he said.

In November, Zheng registered to become an organ donor himself. "When I die and if there is any useful organ, I am willing to help others in need," he said.