Parkinson’s disease also called paralysis agitans or shaking palsy is a movement disorder. Cases of PD are reported at all ages, though it is uncommon in people younger than 40.

This disease is more common among men and usually occurs after 60 years.

The nerve cells in the part of the brain which controls movements are mainly affected. The nerve cells (neurons) which make the chemical called dopamine either don’t work sufficiently or are completely destroyed. The real cause behind this had never been identified. Though, many risk factors have been enumerated in the literature.

Persons suffering from Parkinson’s disease need not present with every common symptom. The number of symptoms and their intensities is known to vary with every individual. Most common signs & symptoms of Parkinson’s include:

These symptoms certainly vary in intensities in different persons. They are seen as the disease progresses and everyone does not suffer from all of them.

We now know that many of the signs and symptoms of Parkinson's disease develop when certain nerve cells (neurons) in an area of the brain called the substantia nigra are damaged or destroyed. Normally, these nerve cells release dopamine — a chemical that transmits signals between the substantia nigra and another part of the brain, the corpus striatum. These signals cause your muscles to make smooth, controlled movements.