A girl diagnosed with a rare medical condition where only half of the heart is fully functional, has stunned the world by surviving for more than 4 months before diagnosis, Daily Mail reports.

The girl, 4 and a half month old Scarlett Dougan, has a condition known as Hypoplastic right heart syndrome (HRHS), where the right side of the heart (the right ventricle and atrium) is improperly developed leading to insufficient blood supply to the lungs.

Babies who suffer from this condition appear to have a bluish tint to their lips, nails, skin and other parts of the body.

Scarlet wasn't diagnosed with the condition until she was four months old. It was her mother, Nichola who felt a difference in the way Scarlet was behaving and consulted a physician.

"Nathanial (Scarlet's older brother who is nearly 2 years old) is such a happy wee boy, everybody knows how happy he is," Nichola said, "but I think people started to think: 'She's wild,' because Scarlett was just so unhappy and screamed all the time," Daily Mail reports.

The child was immediately sent to Yorkhill Hospital for Sick Children in Glasgow. Scarlet has received two major operations since her diagnosis to re-route her blood flow. Doctors say that she might need another operation when she becomes a teenager.

"It is a miracle she is still here," Nichola said. "The doctors can't really believe how a child can get to four and a half months with that condition," she noted to the Daily Mail.