Parkinsonism is any condition that causes a combination of the movement abnormalities seen in Parkinson's disease — such as tremor, slow movement, impaired speech or muscle stiffness — especially resulting from the loss of dopamine-containing nerve cells (neurons). A disorder of the central nervous system that affects movement, often including tremors. Nerve cell damage in the brain causes dopamine levels to drop, leading to the symptoms of Parkinson's. Parkinson's often starts with a tremor in one hand. Other symptoms are slow movement, stiffness and loss of balance. Medication can help control the symptoms of Parkinson's. Parkinsonism is caused by brain disorders, brain injuries, or certain drugs and toxins. People with parkinsonism, like those with Parkinson disease, have tremors that occur when muscles are relaxed, stiff muscles, slow movements, and problems with balance and walking. Doctors try to identify the cause of parkinsonism by asking about conditions known to cause it and by using brain imaging to look for a possible cause. The cause is treated if possible, drugs may be used to relieve symptoms, and general measures (such as simplifying daily tasks) may help people function better.