The gradual and non-specific presentation of Parkinson's disease can make it difficult to diagnose, especially in the early stages of the disease. People who suffer from Parkinson's go to their physician after noticing symptoms such as tremors or trembling, a sense of unbalance, difficulty walking, stiffness, trouble talking, or slowness of movement. Both men and women can be affected by Parkinson's disease, and although there are cases of young-onset Parkinson's, the disease mostly tends to affect people over the age of 50. So how do you know if you have Parkinson's? What tests are available and what can you expect?

Parkinson's disease is not always easy for physicians to diagnose; in fact, some think that up to a quarter of Parkinson's diagnoses are actually incorrect. Unlike many illnesses, there is no one laboratory test or radiological exam that provides a definitive diagnosis of Parkinson's disease. Patients exhibiting Parkinson's-like symptoms may undergo blood and urine tests, or CT or MRI scans to exclude other conditions, but none of these can provide a diagnosis of Parkinson's disease. Other nuclear tests may be useful for helping to diagnose Parkinson's, but at the present time are used more for research purposes rather than as a diagnostic tool.

The most common way to test for Parkinson's disease is thorough systemic neurological and physical examination. This may include tests to gauge the patient's muscle strength, reflexes, coordination, balance, gait, and smoothness of movement.

Clinically, the appearance of Parkinson's disease is noted by the presence of four cardinal signs or key symptoms, including tremors or trembling at rest, rigidity, akinesia and bradykinesia, and postural instability.

Tremors or Trembling: tremors while at rest are one of the easily recognized symptoms of Parkinson's, and it is the first sign to appear for about 70 percent of Parkinson's patients. The hand and leg on one side of the body are most likely to experience tremors in the early stages of the disease.

Bradykinesia and akinesia: these characteristics of Parkinson's are defined respectively as scarcity and slowness of movement. They apply to major movements such as walking, but also to smaller movements such as blinking.

Rigidity: stiffness in the trunk or limbs is known as rigidity and is a classic symptom of Parkinson's disease. Rigidity may appear as a reduced arm swing when walking, making the movement look awkward.

Postural Instability: Parkinson's often results in difficulty walking, impaired balance, or an awkward forward or backward leaning stance.

A physician may make a diagnosis of Parkinson's disease if two of the following three conditions are present: tremors at rest, akinesia and bradykinesia, or rigidity. This is especially so if the two symptoms are noticed in combination with some of the secondary signs of Parkinson's. These include greasy skin, increased sweating, constipation or increased urination, impaired olfactory senses, dizziness when standing, numbness, pain, burning sensations, fatigue, restlessness, difficulty sleeping, or depression.

Physicians may also look for a family history of Parkinson's disease when testing for the illness. Although there are cases where a known genetic mutation causes Parkinson's in a family, more common are the cases of a family history of Parkinson's without a known link.