Parkinson's disease is a neurological disease that begins with mild symptoms and progressively gets worse. No one knows for sure what causes this condition, but there is some evidence that a combination of hereditary and environmental factors is often to blame. Its symptoms are caused by a lack of dopamine production in the brain. The brain stops producing adequate levels of dopamine before symptoms begin, and the symptoms become more pronounced and severe as the disease progresses.
Tremors
According to the Mayo Clinic, the first noticeable symptom of Parkinson's disease is trembling. This often begins in one hand, and the tremors may be limited to only one side of the body in the earlier stages of the disease. As time goes on and the tremors become more pronounced, and they may be worse on the side they started on.
Slow Movement
Slowed motion, also called bradykinesia, is another symptom of progressing Parkinson's disease. People with this condition may shuffle their steps, or be unable to lift their foot to take the first step. According to the Neurology Channel, this is due to slowed impulses from the brain to the muscles of the body, which are caused by the low levels of dopamine.
Rigidity
According to the National Parkinson Foundation, people with Parkinson's disease may have an unblinking and staring facial expression, due to their facial and neck muscles becoming more rigid. This rigidity also extends to the neck, trunk and limbs as the disease progresses.
Loss of Reflexes
The Mayo Clinic states that as time passes, reflexes such as blinking, swinging the arms with walking and smiling will diminish and eventually be lost. People with Parkinson's disease may be unable to gesture or change facial expressions.
Other Symptoms
As Parkinson disease progresses, victims may have trouble speaking clearly, or may speak very quietly or with a slur. Some patients may have problems with their memory, or may suffer from dementia. According to the Neurology Channel, less common symptoms that may occur as the disease progresses include constipation, difficulty swallowing, excessive saliva production, scaly or dry skin and excessive sweating.
