Although Parkinson's disease was first officially recognized in 1817, its symptoms have been documented as far back as 5000 B.C. In the United States, at least 500,000 people are estimated to have this chronic and progressive disease, and approximately 50,000 new cases are reported each year. In many cases, the first noticeable sign of Parkinson's disease is a tremor. This characteristic symptom tends to start on one side of the body, most often in one hand. It is typically obvious during rest, and improves with activity. Possible treatment options for this disease include medications, lifestyle changes, and surgery.