Parkinson’s disease is a condition that affects the nervous system, and as a result, the ability to control body movements. The disease develops gradually, often starting with tremors in just one hand or stiffness and slowing of movement. The early stages of Parkinson’s disease may be characterized by difficulty showing facial expressions or swinging the arms while walking. As time goes on, symptoms such as soft or slurred speech, rigid muscles, slowed movement, loss of automatic movements, balancing problems and writing changes may develop. While Parkinson’s disease cannot be cured, frequent exercise and medications can help improve symptoms and prevent the condition from progressing.