A scientist researching a way to stall Parkinson's disease says the rate of New Zealanders getting it is on the rise.
Today is World Parkinson's Day and about 12,000 New Zealanders live with the diagnosis.
University of Auckland research fellow Victor Dieriks said it was sad a treatment had not yet been found.
"Because the first paper written on Parkinson's is from 1817 by James Parkinson. So in over 200 years we have not found one single treatment that treats the underlying disease.
"We can treat the symptoms but not the underlying disease."
He said the rise in cases was linked to the ageing population, but other factors were contributing.
"We know that exposure to pesticides, imbalance in metals, people working in mines, have a higher chance of getting Parkinson's and now we're seeing people who have had Covid-19 are more prone to getting Parkinson's as well."
He said in Parkinson's protein clumps formed in the organ which allowed us to smell, however the protein clumps were toxic to the neighbouring cells.
"When there's too much of it, it starts killing the cells around it and parts of the brain no longer work anymore."
"At one point it reaches a central part of the brain, and [when it gets there] we start seeing the tremor and the shaking."
The research aims to slow the time it takes for the protein clumps to move from the nose to the brain.
"One of the early symptoms is they lose their sense of smell, about 5 to 10 years before the tremors start happening and it's mostly unnoticeable and blamed on old age.
"My aim is to make sure the timeframe between losing your sense of smell and the more severe symptoms... is to prolong that period."
Dieriks said on World Parkinson's Day it was important to remember the families of those living with it.
"We can't disregard the families of people with Parkinson's because it's a disease that affects the whole family... looking after someone with Parkinson's is a full time job."