context: Parkinson's disease is an illness that affects the part of your brain that controls how you move your body. It can come on so slowly that you don't even notice it at first. But over time, what starts as a little shakiness in your hand can have an impact on how you walk, talk, sleep, and think. You're more likely to get it when you're 60 and older. It's also possible for it to start when you're younger, but that doesn't happen nearly as often. There's no cure for Parkinson's disease, but you can get treatment and support to help manage the symptoms. Deep down in your brain, there's an area called the substantia nigra. Some of its cells make dopamine, a chemical that carries messages around your brain. When you need to scratch an itch or kick a ball, dopamine quickly carries a message to the nerve cell that controls that movement. When that system is working well, your body moves smoothly and evenly. But when you have Parkinson's, the cells of your substantia nigra start to die. There's no replacing them, so your dopamine levels drop and you can't fire off as many messages to control your body. Early on, you won't notice anything different. But as more and more cells die, you reach a tipping point where you start to have symptoms. That may not be until 80% of the cells are gone, which is why you can have Parkinson's for quite a while before you realize it. The telltale symptoms all have to do with the way you move. You usually notice problems like: Rigid muscles. It can happen on just about any part of your body. Doctors sometimes mistake early Parkinson's for arthritis. Slow movements. You may find that even simple acts, like buttoning a shirt, take much longer than usual. Tremors. Your hands, arms, legs, lips, jaw, or tongue are shaky when you're not using them. Walking and balance problems. You may notice your arms aren't swinging as freely when you walk. Or you can't take long steps, so you have to shuffle instead. Parkinson's can also cause a range of other issues, from depression to bladder problems. Doctors aren't sure why all those brain cells start dying. They think it's a mix of your genes and something in the environment, but the reason is not straightforward. Someone could have a change in a gene tied to Parkinson's, but never get the disease. That happens a lot. And a bunch of people could work side by side in a place with chemicals linked to Parkinson's, but only a few of them end up with it. It's a complex puzzle, and scientists are still trying to put all the pieces together. There's no one test for Parkinson's. A lot of it's based on your symptoms and health history, but it could take some time to figure it out. And part of the process is ruling out other conditions that look like Parkinson's. That's one reason it's important to go to a doctor who knows a lot about it. Early on, it's easy to miss. If you do have it, your doctor might use what's called the Hoehn and Yahr scale to tell you what stage of the disease you're in. It ranks how severe your symptoms are from 1 to 5, where 5 is the most serious. The stage can help you get a better feel for where your symptoms fall and what to expect as the disease gets worse. But keep in mind, some people could take up to 20 years to move from mild to more serious symptoms. For others, the change is much faster. It's all about managing symptoms. Drugs for Parkinson's can often help with tremors, stiff muscles, and slow movements. Your doctor may also suggest physical therapy, occupational therapy, and speech therapy, based on how it affects you. And in some cases, you may need surgery. Most people who have Parkinson's live a normal to a nearly normal lifespan, but the disease can be life changing. For some people, treatment keeps the symptoms at bay, and they're mostly mild. For others, the disease is much more serious and really limits what you're able to do. As it gets worse, it makes it harder and harder to do daily activities like getting out of bed, driving, or going to work. Even writing can seem like a tough task. And in later stages, it can cause dementia. Even though Parkinson's can have a big impact on your life, with the right treatment and help from your health care team, you can still enjoy the things you love. It's important to reach out to family and friends for support. Learning to live with Parkinson's means making sure you get the backing you need.