Parkinson’s is a degenerative disease that affects the nervous system and causes sufferers to lose control of their movements. It can also affect cognition and behavior. The exact cause of Parkinson’s is unknown, but the mechanism has been identified as hypodopaminergic. This simply means that there is a lack of dopamine in the brain. Without sufficient dopamine, which is a crucial neurotransmitter that affects movement, the body loses control of its muscles. The disease is largely thought to be genetic, although people with heart disease, brain tumors, and certain viruses are also at risk, as are those who have taken the drugs haloperidol and metoclopramide.