Mr Bohana's current symptoms are tremors to his left arm, severe muscle stiffness every time he does any form of activity, loss of smell, sensory neuropathy (loss of feeling to the right leg when doing exercise) and moderate vertigo.
“I took up running to prove that being diagnosed with Parkinson's does not mean you cannot continue to enjoy life,” said Mr Bohana.
He continued: “There are many stories about people who have often been diagnosed at a much younger age, and exercise to help slow down the rate of Parkinson’s.
“The release of the chemical Serotonin, which happens through exercise, is shown to help slow down the rate of the disease.
“I have been especially motivated by the stories of other sufferer's and how they have tried to overcome their issues through determination and a lot of pain.”
Andrew is aiming to finish the marathon in under 5.5 hours, and then his next target will be Eryri Marathon this Autumn!
“To give you an idea of what it is like for me to undertake this challenge, imagine having to run a short distance, but it is continually uphill even if you are on the flat,” he said.
“Your legs start feeling like they are set in concrete and the left arm trembles uncontrollably.
“Numbness to the right leg and constant pins and needles for the entire duration of running.
“You know you cannot stop because once you do, the whole body will start shaking and the muscles are aching to the point of exploding. It is tough, but I am certain through change in diet and exercise, I can give myself a better quality of life.”
On Sunday Andrew will be wearing his lucky woolly hat, he has worn since he started running.
He’s raising money for the charity Cure Parkinson’s and since he shared his story online it has meant the world to him that so many staff and his former pupils from over the years have sponsored him. Pob Lwc Sir on Sunday, and we are all very, very proud of you.
If you would like to sponsor Mr Bohana please follow this link-