What Are The Stages Of Parkinson's Disease?

Parkinson's Disease, named for Dr. James Parkinson who first identified it in 1817, is a neurodegenerative disease that impacts nerve cells in the brain, according to the Parkinson Foundation. The loss of nerve cells lowers the amount of dopamine in the brain — and because dopamine is a neurotransmitter that communicates with parts of the brain that are responsible for coordination and movement, the disease manifests with a number of motor symptoms, though there are nonmotor symptoms as well. Parkinson's Disease is the second most prevalent neurodegenerative disease after Alzheimer's, affecting approximately one million Americans and six million people around the globe.

Parkinson's is a progressive disease, meaning that symptoms typically won't improve but will instead get worse as time goes on (via National Institute on Aging). Symptoms usually include tremor, loss of coordination and balance, slow movement, and muscle stiffness. Other symptoms include fatigue, depression, memory troubles, and sleep issues. 

There is no cure for the disease, though therapies are available to treat symptoms. Medications like levodopa are helpful for increasing the levels of dopamine in the brain, which can also affect levels of other important neurotransmitters. Deep brain stimulation can help those who might be resistant to medications, as well as physical, occupational, and speech therapies. While Parkinson's typically develops after the age of 60, in about 5-10% of cases, onset is before the age of 50.

When a diagnosis of Parkinson's is made, doctors will use the Hoehn and Yahr rating scale to determine how severe the symptoms are (via Healthline). This scale divides results up into five stages, which will tell you how much the disease has progressed.

In the first stage, symptoms often present on only one side of the body. They're often so mild that might even be missed, only noticed by family or friends who point out differences in facial expressions or walking. Progression to Stage 2 can happen quickly or slowly depending on the person, and symptoms will become much more noticeable than in stage 1. Muscle stiffness can make tasks take longer to complete, though you probably won't experience issues with balance yet. Tremors and having difficulty walking become more prominent in stage 2.

In the third stage, there's a turning point in the progression of Parkinson's. Movements become much slower, making falls more likely to happen as balance and reflexes become compromised. The major difference between stage 3 and 4 is in independence: In stage 4, you often will not be able to walk or move around without some kind of assistance, making it dangerous to live alone. In stage 5, the most advanced stage, muscles become so stiff that you're unable to stand or walk at all, often needing a wheelchair to get around. Mental difficulties become prominent as well, with up to 50% of patients in stages 4 and 5 experiencing hallucinations, delusions, and confusion. Healthline notes, though, that each individual with Parkinson's will experience a unique progression of the disease, and some will never reach the most advanced stage.