Parkinson's disease is a progressive neurological disorder that results from degeneration of neurons in a region of the brain that controls movement. Parkinson's disease (PD) belongs to a group of conditions called motor system disorders, which are the result of the loss of dopamine-producing brain cells.
The primary symptoms of Parkinson's disease are:
Tremors or trembling in hands, arms, legs, jaw, and face
Rigidity, or stiffness of the limbs and trunk
Bradykinesia, or slowness of movement
Inability to move (akinesia)
Impaired balance and coordination
Slow movement (bradykinesia)
A shuffling gait
Foot pain and toe curling
Difficulty swallowing or chewing
As these symptoms become more pronounced, patients may have difficulty walking, talking, or completing other simple tasks. Parkinson’s disease usually affects people over the age of 50. Early symptoms of PD are subtle and occur gradually. In some people the disease progresses more quickly than in others.
As the disease progresses, the shaking, or tremor, which affects the majority of people with Parkinson’s may begin to interfere with daily activities. Other problems associated with Parkinson’s include:
Depression and other emotional changes
Difficulty in swallowing, chewing, and speaking
Urinary incontinence or constipation
Sleep disruptions due to movement in sleep
There are currently no blood or laboratory tests that have been proven to help in diagnosing sporadic PD. Therefore the diagnosis is based on medical history and a neurological examination. The disease can be difficult to diagnose accurately. Doctors may sometimes request brain scans or laboratory tests in order to rule out other diseases.
Source: The National Institutes of Neurological Disorders and Stroke (NINDS). https://www.ninds.nih.gov/Disorders/All-Disorders/Parkinsons-Disease-Information-Page