Two Chinese doctors who were in critical condition after being infected with coronavirus have seen their skin turned dark after recovering from the deadly disease.

Dr. Yi Fan and Dr. Hu Weifeng, both 42, were diagnosed with COVID-19 while treating patients at the Wuhan Central Hospital in January. The darkening of their skin colour was attributed to hormonal imbalance that took place in the body as a result of their livers being damaged by the virus, Chinese state media reported.

Dr. Li, who has been treating Dr. Yi and Dr. Hu suspects that the two doctors' skin turned dark due to a type of medicine they were given during the early stages of their treatment. He added that one of the drug's side effects is the darkening of one's skin colour. Although he did not identify the drug, Dr. Li expected both doctors' skin colour to return to normal once their livers start functioning properly.

Colleagues of late coronavirus whistle-blower

Dr. Yi and Dr. Hu were colleagues of the late whistle-blower Li Wenliang, who was reprimanded by Chinese authorities for raising an alarm over the deadly pathogen. Wenliang died from the disease in February.

The two doctors were diagnosed on Jan 18 and were admitted to the Wuhan Pulmonary Hospital for treatment before being transferred twice, as pointed out by Chinese state broadcaster Beijing TV.

How are both doctors responding to treatment?

Dr. Yi, a cardiologist by profession, was hooked to a life-support machine called ECMO and took 39 days to recover from COVID-19. ECMo is a drastic life-support procedure which actually replaces the function of the heart and lungs by the process of pumping oxygen into the blood from outside the body.

Dr. Yi said the ordeal of battling coronavirus has left him traumatised. "When I first gained conscious, especially after I got to know about my condition, I felt scared. I had nightmares often," he told a reporter. The doctor was given counselling to overcome the trauma and while Dr. Yi can move around in bed on his own he cannot walk independently.

Dr. Hu's condition was more serious. The urologist was bedridden for 99 days and is still being looked after in the hospital's intensive care unit. Dr. Li claims the coronavirus treatment has taken a toll on his mental health and only recently regained his ability to speak. Dr. Hu also received the same ECMO treatment as his colleague.