He also used to be able cry, sweat, chew, swallow and touch his toes.

But now the Mount Helen 24-year-old can't do any of them, thanks to two bouts of acute myeloid leukaemia that has left him with chronic graft versus host disease (GvHD).

Basically, the second bone marrow transplant that saved his life is now attacking him.

"Your body literally tears itself apart," Mr McNally said.

His skin is tight and scarred, similar to a burns victims, and is paper thin and peels easily.

A year ago, he also suffered heart failure which left his heart functioning about 20 per cent, while his lungs operate at 50 per cent due mainly to ongoing infections.

Mr McNally's story began in October, 2003 when he had a sleepover at a friend's place during grade six.

He woke feeling lethargic and aching all over.

After he became sensitive to light, his parents took him to emergency before he was sent to the Royal Children's Hospital, where his leukaemia diagnosis was confirmed.

"They told me my blood was so thick it was like honey."

Six rounds of chemotherapy, radiation therapy and a bone marrow transplant from his mother Sandra, who was luckily a six out of six match, followed.

During his recovery, Mr McNally suffered a mild bout of GvHD but it disappeared over the following 12 months.

From 2005 to 2009, he lived a normal teenage life, even attending a Challenge cancer support group camp in America.

But just before finishing year 12 at Mt Clear College, Mr McNally's white blood cell count went up - and didn't come back down.

Now nearly 19, he was admitted to the Royal Melbourne Hospital where he underwent intensive chemotherapy before his mother's stem cells were introduced into his system to induce GvHD to kill the cancer.

However, it didn't work and he again received a bone marrow transplant from an unrelated matched donor.

"It worked, it got rid of the cancer and for the first six to 12 months I was not good but better."

Unfortunately, though, the GvHD returned in a chronic form and, six years later, hasn't disappeared.

While he is on immunosuppressants, for the last 18 months he has also been undergoing photopheresis at Peter McCallum Cancer Centre, where his blood is removed and treated with a photosensitizing agent and light irradiation.

"The improvement has been quite impressive. The therapy definitely works. It made a big difference to me."

So now Mr McNally is giving back by raising funds for GvHD research and treatments.

"Life is short and precious and should not be wasted. So donate, donate, donate away. Small is good, even a dollar. Large is awesome and I would kiss you!"

To donate, go to gofundme.com/cheesiehamham.

fiona.henderson@fairfaxmedia.com.au