Parkinson's (Movement Disorders)
Parkinson's disease is a progressive disorder of the central nervous system, meaning symptoms get worse over time. Its symptoms -- tremors (often starting in one hand), slowed movement, rigidity -- are caused when nerve cells in the brain that produce a chemical called dopamine start to break down and die. Dopamine is a neurotransmitter, or messenger, that sends messages to the parts of the brain that control movement. Parkinson’s disease affects men and women equally, usually after age 60. About 10% of people with the disease are under age 40. No cure is available, but drug therapy can help reduce the symptoms.