Elderly Care in Houston TX: People with Parkinson’s disease (PD) may experience a variety of symptoms. And, what one person experiences, the next may not. Usually, the symptoms of PD start when a person is between age 50 and age 60. They develop gradually and worsen over time. One symptom that is common in most people with PD is tremors. They occur in about 80 percent of people with the disease and can be one of the more difficult symptoms to deal with.