Parkinsonism is characterized by four main clinical features:

• Bradykinesia (slowness and paucity of movement)
• Rigidity (stiffness)
• Tremor (usually resting)
• Postural instability

The initial presenting symptoms can be quite variable and may include:

• Change in facial expression (staring, lack of blinking)
• Failure to swing one arm when walking
• Flexion (stooped) posture
• "Frozen" painful shoulder
• Limping or dragging of one leg
• Numbness, tingling, achiness or discomfort of the neck or limbs
• Softness of the voice
• Subjective sensation of internal trembling
• Resting tremor

Tremor is, of course, quite characteristic but is not universally present at onset and up to 30% of patients never develop a substantial tremor. The tremor is most prominent at rest, disappears with movement, but may also be present when maintaining a posture. This tremor is usually a rhythmic shaking in the relaxed hand that goes away when the hand is used. Tremors can also occur in the leg or the jaw. A tremor which occurs only with action is not Parkinson's. .

Sometimes the symptoms first appear only in one arm or leg, with a loss of one arm’s swing when walking or a dragging of one foot. Early signs of Parkinson’s disease can sometimes be mistaken for a stroke because only one side of the body seems impaired.