What is the primary symptom of Parkinson’s disease?

The primary symptom of Parkinson’s disease is a tremor at rest. This characteristic resting tremor is often one of the first noticeable signs of Parkinson's and is typically observed when the affected individual is relaxed and not engaging in purposeful movements. It usually starts in one hand and can manifest as a rhythmic shaking motion, which may also be accompanied by changes in the amplitude and frequency as the disease progresses.

In Parkinson’s disease, the tremor is caused by underlying neurological changes resulting from the loss of dopamine-producing neurons in the brain. These tremors are distinct from action tremors that occur during movement or when trying to maintain a posture.

While stiffness in muscles, difficulty walking, and memory loss can also occur in patients with Parkinson's, they are not considered primary symptoms. Muscle stiffness can contribute to the overall motor difficulties experienced by patients, and gait disturbances become evident as the disease progresses, but these symptoms typically emerge after the initial tremor. Memory loss is not a primary feature of Parkinson's; it may arise later in the disease or due to associated conditions but is not one of the hallmark symptoms used for diagnosis. In summary, the resting tremor is a classic sign that helps in identifying and diagnosing Parkinson’s disease.