Like most teenagers of age, Finley celebrates his birthday every year for the cake, but he can never eat it or anything else. If he does, he will bleed inside.

The 14-year-old's digestive system can't stand lipids - fatty compounds or oils found in foods - so he injected them directly into his heart.

This treatment is a six-hour process that he has experienced every week since he was four and has increased to twice a week over the past year as he grew.

Finley's case is so rare that doctors have considered presenting it to medical journals because they think he might be one of the only people who respond to lipids in this way.

Dr. Manas Datta, a consultant pediatrician at Broomfield Hospital in Chelmsford, Essex, who has treated Finley since birth, said it was "terrifying" to see Finley's body's reaction to food.

"Even if he's on breast milk, he's reacting." Dr. Data told the BBC.

"We've never seen such a case before - I remember many days when Finley came to the hospital so uncomfortable."

Finley, from Battlesbridge, Essex, has undergone more than 20 surgeries at Great Ormond Street Hospital in London as doctors try to understand his condition.

His mom, 37, Rhys, now 37, felt her son became a "guinea pig" due to "trial and errors," and it was "a light bulb moment" when doctors finally figured out how to treat her son.

"Sometimes it's heartbreaking - people can't see what Finley is doing every day," she said.

“They saw a happy, hoarse young man, but psychologically, he went through a lot.”

Rhys said she would not try to hide the social aspects of food.

"He always helps with cooking, we always go to restaurants, he always has birthday cakes," she told the BBC.

"He may not be able to eat it, but he is normal in this regard as everyone else."

Finley, who is also autistic, says the appearance and smell of food does not make him hungry or feel missing.

He added: "Having my feed is what I know, so I only see other people eating and that won't bother me."

Finley receives a lipid infusion through Portacath or Tube, which goes into his chest and connects directly to the central vein in his heart.

"We have to completely bypass the gastrointestinal tract," Dr. Data said.

"Not only fat, but he can't even stand normal carbohydrates and protein," he added.

Finley receives carbohydrates and proteins as well as vitamins, minerals and electrolytes three times a day through different tubes.

"I don't remember when I (infusion) is because it's just my life - I can't really escape it," Finley said.

"There is no name for Finley," Rhys said.

“No one else knows to inject lipid elements directly.”

"We are actually considering reporting the case to a diary of some kind because it's a rare situation," Dr. Data said.

Hopefully Finley will eventually be able to undergo infusion treatment at home instead of heading to Broomfield Hospital twice a week.

"Sometimes he might endure fat, but if not, we just keep going 'normal' and move on from there," Rhys said.

Finley plans to land on May 16 at a tower at Southend Hospital to raise funds for Central and South Essex Hospital charities.

"The building is 154 feet (47m) - a little tall, but I think I'll be fine," Finley said.

“The hospital and all (the staff) gave me a lifetime of care and I just wanted to give back and raise funds for them to help others.”

Finley's Mom - A few years ago, he completed the same Abseil on behalf of Finley.

“He is the cutest little boy, he wants to help others because he has gone through his experiences – I’m proud of him.”