What is the biggest cause of Parkinson's?

What Triggers Parkinson’s Disease?

While scientists haven’t pinned down a single cause for Parkinson’s disease, most experts agree it’s likely the result of a complex interplay between genetics and environmental factors. “We think it's probably a combination of environmental exposure — to toxins or pesticides — and your genetic makeup,” explains Dr. Dawson, a leading researcher in neurodegenerative disorders.

One of the most significant risk factors, however, is something no one can avoid: age. The average age of onset is around 60, and the likelihood of developing Parkinson’s increases as we grow older. This doesn’t mean younger people are immune—some do develop early-onset forms—but the risk climbs steadily with advancing years.

Environmental exposures may also play a key role. Long-term contact with certain chemicals, particularly pesticides and herbicides, has been linked to a higher risk of the disease, especially among agricultural workers. Still, not everyone exposed develops Parkinson’s, suggesting that genetics may determine who is more vulnerable.

Genes alone rarely tell the whole story. While mutations in certain genes are associated with Parkinson’s, especially in early-onset cases, most patients don’t have a clear family history. Instead, researchers believe multiple genes may contribute, each adding a small amount to overall risk—especially when combined with environmental triggers.

In the end, Parkinson’s likely arises from a “perfect storm” of aging neurons, genetic susceptibility, and external insults. Understanding how these pieces fit together is key to unlocking better treatments—and one day, prevention. For now, age remains the biggest red flag, but the full picture is anything but simple.