Parkinson's Disease

Diagnosis & Tests

There are no blood tests or imaging studies, like CT scans or MRI scans, that can diagnose Parkinson’s disease. Healthcare professionals usually diagnose Parkinson’s based on a person’s medical history and symptoms.

Diagnosis can be difficult, especially in the early stages of disease when symptoms are mild. This is because some of the symptoms, such as slowed movements, stiffness and balance problems, can also occur with normal aging or with other disorders. 

Usually, to make a diagnosis of Parkinson’s disease, a person must have bradykinesia (slow movement), and at least one of the other main symptoms: Tremor and rigidity (muscle stiffness). Other things your healthcare provider will look for and ask about are if symptoms began on one side of the body, and if the tremor occurs at rest (these symptoms suggest that Parkinson’s disease is more likely). Your provider will also ask about other medical conditions you may have, medications that you are taking, and whether you have a history of falls or difficulty walking. Patients should also tell their provider about changes in mood, thinking, sleep, or bowel and bladder function.  

Your healthcare provider will do a physical examination checking for tremor, bradykinesia, and rigidity. The provider will also check reflexes, balance while walking and standing, and ability to perform certain tasks with the hands.

Sometimes, healthcare providers will do a “medication challenge” to help make the diagnosis of Parkinson’s disease. If the motor symptoms improve significantly with medications for Parkinson’s disease, this supports the diagnosis. If the motor symptoms do not improve, a different diagnosis is more likely.

Last Updated October 2020