One of a group of conditions called movement disorders, Parkinson's disease is characterized by muscle rigidity, tremors, and a slowing of physical movements.

In addition, there may be some language problems and reduced cognitive function. There is no cure, so Parkinson's disease is both chronic and progressive.

Parkinson's disease can be difficult to diagnose accurately as there are no blood or laboratory tests that can effectively help in diagnosis. Diagnosis is therefore based on medical history and a neurological examination. The main symptoms include:

Tremors: Worse when the limb is at rest, and subject to some control
Rigidity: Stiffness and increased muscle tone - when combined with tremors, this can make the limb difficult to control
Slowness or absence of movement
Postural instability: Impaired balance resulting in falls

There are a variety of possible causes, including a genetic component, toxins, head trauma, or as a side effect of some medications.

As there is no cure, this is a disorder that will become progressively worse. Treatment therefore focuses on management of the symptoms, with a range of modalities including patient and family education, support groups, exercise, and nutrition.

In addition, medications and surgery can sometimes provide relief from the symptoms.