Classic symptoms are shaking, stiff muscles and slow movement. People with an advanced case also may have stooped posture, a fixed look on the face, speech problems or problems with balance or walking. They may also experience a loss of intellect. Tremor (shaking) usually is the first symptom people notice. Unlike most other tremors, the "resting" tremor is worse when the person is awake but not moving around. Emotional and physical stress tends to make the tremor worse. Sleep, complete relaxation and intentional movement or action usually reduce or stop the tremor. Up to 25 percent of people with Parkinson's disease do not experience tremors.
The muscles of the legs, face, neck or other parts of the body may go rigid. Another common early sign of the disease is a reduced swing of the arm on one side when the person is walking.
Parkinson's disease can cause a variety of other disabilities:
- Less dexterity and coordination. Changes in handwriting are common, with writing becoming smaller. Athletic skills decline, and daily activities (such as dressing and eating) become harder.
- Weakness of face and throat muscles. Talking and swallowing may become more difficult. Choking, coughing or drooling may occur. Speech becomes softer and monotonous.
- Loss of movement in the muscles in the face, including around the eyes, can cause a fixed, vacant look on the face.
- Cramps in the muscles and joints
- Oily skin or increased dandruff
- Constipation and problems controlling or starting urination
- Problems with involuntary or automatic body functions. These include more sweating, low blood pressure when the person stands up and problems with sexual function.
- "Freezing," a sudden, brief inability to move, most often affects walking
- Problems falling asleep or staying asleep can result from anxiety, depression or a feeling of restlessness. Patients may not be able to sleep well. They cannot easily turn over or change position in bed.
A person may slowly become more dependent, fearful, indecisive and passive. The person may talk less often, withdraw from people and be inactive unless encouraged to move about. Depression is very common with this disease. It can be caused by chemical changes in the brain, or it can be a reaction to having a disabling disease. Depression often improves with proper treatment.
Up to one-third of patients may develop dementia and confusion. This is similar to Alzheimer's disease. Depression can add more memory loss and confusion. These symptoms, as well as hallucinations (seeing or hearing things that aren't really there), and vivid dreams may be caused by drugs taken to treat the disease.
Causes and Risk Factors
Although some forms are genetic, the causes for most forms of Parkinson's disease are unknown. Studies of environmental and inherited factors are starting to offer clues.