The four major symptoms of Parkinson's disease are:

•  Rigidity - stiffness when the arm, leg, or neck are moved
• Resting tremor - tremor most prominent at rest, when sitting quietly
• Bradykinesia - slowness in initiating movement which may contribute to decreased facial expression, change in speech pattern, shuffling gait, smaller-lettered handwriting, trouble with fine finger movements.
•  Loss of postural reflexes - poor balance and coordination 

In addition, a number of other findings that are associated with Parkinson's disease include mask like face, micrographia, emotional lability, depression, sleep problems and change in speech pattern.

Not every one with Parkinson's disease experiences the same symptoms. The speed at which symptoms appear in each individual also differs. Hence few people have an accelerated progress of the disease where as some people remains static and slowly progressive in their disease. The disease is never symmetrical on both the sides. It usually affects one side of the body first followed by the involvement of the other side of the body at the later stage.

About 60% of the people with Parkinson's disease experience resting tremor. Symptoms often begin with occasional trembling of one hand that gradually becomes constant. The tremor can progress to the other hand, to the legs and occasionally to the face. However in some patients first manifestation of the disease is bradykinesia i.e. slowness of body activities.

There are many other diseases that can present with parkinsonian symptoms. However they are different in their progress, response to treatment and outcome, than Parkinson's disease. This includes diseases like multi-system atrophy, progressive supranuclear palsy (PSP), cortico-basal ganglionic degeneration (CBGD), etc.

Although tremors would seem to be the biggest problem with the people suffering from Parkinson's disease, the most frustrating symptoms are the symptoms associated with slow movements and gait disturbances. As a result, people with this disease often have trouble dressing, handling utensils, eating, and with personal hygiene. They may also experience difficulty in rising from chair, turning in bed, or getting in and out of car. Without treatment, pronounced disability occurs in about 9 years. However current symptomatic medication may control progression and patients continue to do well longer.

There are no laboratory tests or radiological investigations to diagnose Parkinson's disease. The diagnosis of the disease still remains a clinical judgment. The Parkinson's disease disabilities can be assessed by Unified Parkinson's disease rating score (UPDRS), Schwab and England activities of daily living score and Hoehn and Yahr scoring. 

• 0-none
• 1-mild. Consistent forgetfulness with partial recollection of events with no other difficulties
• 2-moderate memory loss with disorientation and moderate difficulty handling complex problems
• 3-severe memory loss with disorientation to time and often place, severe impairment in handling problems
• 4-severe memory loss with orientation only to person, unable to make judgments or solve problems

• 0-none
• 1-vivid dreaming
• 2-"benign" hallucination with insight retained
• 3-occasional to frequent hallucination or delusions without insight, could interfere with daily activities
• 4-persistent hallucination, delusions, or florid psychosis.

• 0-not present
• 1-periods of sadness or guilt greater than normal, never sustained for days or weeks
• 2-sustained depression for 1 week or more
• 3-sustained depression with vegetative symptoms (insomnia, anorexia, loss of interest, weight loss)
• 4-Sustained depression with vegetative symptoms and suicidal thoughts or intent

• 0-normal
• 1-Less assertive than usual; more passive
• 2-Loss of initiative or disinterest in elective (non-routine) activities
• 3-Loss of initiative or disinterest in day to day (routine) activities
• 4-Withdrawn, complete loss of motivation

• 0-normal
• 1-mildly affected, no difficulty being understood
• 2-moderately affected, Sometimes asked to repeat statements.
• 3-severely affected, frequently asked to repeat statements
• 4-unintelligible most of the time

• 0-normal
• 1-slight but definite excess of saliva in mouth, may have nighttime drooling
• 2-moderately excessive saliva, may have minimal drooling
• 3-marked excess of saliva with some drooling
• 4-marked drooling, requires constant tissue or handkerchief.

• 0-normal
• 1-rare choking
• 2-occasional choking
• 3-requires soft food
• 4-requires NG tube or gastrostomy feeding

• 0-normal
• 1-slightly small or slow
• 2-moderately slow or small; all words are legible
• 3-severely affected; not all words are legible
• 4-majority of words are not legible

• 0-normal
• 1-somewhat slow and clumsy but no help needed
• 2-can cut most foods, some help needed
• 3-food must be cut by someone, but can feed self
• 4-needs to be fed

• 0-normal
• 1-somewhat slow, no help needed
• 2-occasional help with buttoning, getting arms in sleeves
• 3-considerable help required but can do some things alone 
• 4-helpless

• 0-normal
• 1-somewhat slow but no help needed
• 2-needs help to shower or bathe; or very slow in hygienic care
• 3-requires assistance for washing, brushing teeth, combing hair, going to bathroom
• 4-Foley's catheter or other mechanical aids

• 0-normal
• 1-somewhat slow and clumsy but no help needed
• 2-can turn alone or adjust sheets but with great difficulty
• 3-san initiate but not turn or adjust sheets alone
• 4-helpless

• 0-none
• 1-Rare falling
• 2-Occasionaly falls, less than one per day
• 3-Falls an average of once daily
• 4-Falls more than once daily

• 0-normal
• 1-rare, may have start hesitation
• 2-occasional freezing
• 3-frequent freezing, occasional falls from freezing
• 4-frequent falls from freezing

• 0-normal
• 1-mild difficulty may not swing arms or may tend to drag
• 2-moderate difficultly but requires little or no assistance
• 3-severe disturbance of walking, requiring assistance
• 4-cannot walk at all even with assistance

• 0-absent
• 1-slight and infrequent
• 2-moderate, bothersome to patient
• 3-severe, interfere with many activities
• 4-marked, interferes with most activities

• 0-none
• 1-occasionally has numbness, tingling, and mild aching
• 2-frequent, but not distressing
• 3-frequent painful sensation
• 4-excruciating pain

• 0-normal
• 1-slight loss of expression, diction, volume
• 2-monotone, slurred but understandable, moderately impaired
• 3-marked impairment, difficult to understand
• 4-unintelligible

• 0-Normal
• 1-slight hypomymia, could be normal "poker face"
• 2-slight but definite abnormal diminution in facial expression  
• 3-moderate hypomimia; lips parted some of the time
• 4-masked or fixed facies, lips parted 1/4 of inch or more with complete loss of expression

• 0-absent
• 1-slight and infrequent
• 2-mild in amplitude and persistent. Or moderate in amplitude, but only intermittently present.
• 3-moderate in amplitude and present most of the time
• 4-marked in amplitude and present most of the time

• 0-absent
• 1-slight; present with action
• 2-moderate in amplitude; present with action
• 3-moderate in amplitude with posture holding and action
• 4-marked in amplitude; interferes with feeding

• 0-absent
• 1-slight or detectable only when activated by mirror or other movements
• 2-mild to moderate
• 3-marked but full range of motion easily achieved
• 4-severe, range of motion achieved with difficulty

• 0-normal
• 1-mild slowing, and/or reduction in amplitude.
• 2-moderately impaired. Definite and early fatiguing, may have occasional arrests in movement.
• 3-severely impaired. Frequent hesitation in initiating movements or arrests in ongoing movement.
• 4-can barely perform the task

• 0-normal
• 1-mild slowing, and/or reduction in amplitude.
• 2-moderately impaired. Definite and early fatiguing, may have occasional arrests in movement.
• 3-severely impaired. Frequent hesitation in initiating movements or arrests in ongoing movement.
• 4-can barely perform the task

• 0-normal
• 1-mild slowing, and/or reduction in amplitude.
• 2-moderately impaired. Definite and early fatiguing, may have occasional arrests in movement.
• 3-severely impaired. Frequent hesitation in initiating movements or arrests in ongoing movement.
• 4-can barely perform the task

• 0-normal
• 1-mild slowing, and/or reduction in amplitude.
• 2-moderately impaired. Definite and early fatiguing, may have occasional arrests in movement.
• 3-severely impaired. Frequent hesitation in initiating movements or arrests in ongoing movement.
• 4-can barely perform the task

• 0-normal
• 1-slow, may need more than one attempt
• 2-pushes self up from arms or seat
• 3-tends to fall back may need multiple tries but can arise without assistance
• 4-unable to arise without help

• 0-normal erect
• 1-slightly stooped posture, could be normal for older person
• 2-moderately stooped posture, definitely abnormal; can be slightly leaning to one side
• 3-severely stooped posture with kyphosis; can be moderately leaning to one side
• 4-marked flexion with extreme abnormality of posture

• 0-normal
• 1-walks slowly, may shuffle with short steps, no festination or propulsion
• 2-walks with difficulty but requires little or no assistance; may have some festination, short steps or propulsion
• 3-severe disturbance of gait, requiring assistance
• 4-cannot walk at all even with assistance

• 0-normal
• 1-Retropulsion but recovers unaided
• 2-absence of postural response; would fall if not caught
• 3-very unstable, tends to loose balance spontaneously
• 4-unable to stand without assistance

• 0-none
• 1-minimal slowness, giving movement a deliberate character; could be normal for some persons. Possibly reduced amplitude
• 2-mild degree of slowness and poverty of movement which is definitely abnormal. Alternatively, some reduced amplitude
• 3-moderate slowness, poverty or small amplitude of movement
• 4-marked slowness, poverty or small amplitude of movement

• 100%-Completely independent. Able to do all chores without slowness, difficulty, or impairment. Essentially normal. Unaware of any difficulty.
• 90%-Completely independent. Able to do all chores with some degree of slowness, difficulty and impairment. May take twice as long. Beginning to be aware of difficulty.
• 80%-Completely independent in most chores. Takes twice as long. Conscious of difficulty and slowness
• 70%-Not completely independent. More difficulty with some chores. Three to four times as long in some Must spend a large part of the day with chores.
• 60%-Some dependency. Can do most chores, but exceedingly slowly and with much effort. Errors; some impossible
• 50%-More dependent. Help with half of chores. Difficulty with everything
• 40%-Very dependent. Can assist with all chores, but few alone
• 30%-With effort, now and then does a few chores alone or begins alone. Much help needed
• 20%-Nothing alone. Can do a slight help with some chores. Severe invalid
• 10%-Totally dependent, helpless. Complete invalid.
• 0%-Vegetative functions such as swallowing, bladder and bowel functions are not functioning. Bedridden.

• Signs and symptoms on one side only
• Symptoms mild
• Symptoms inconvenient but not disabling
• Usually presents with tremor of one limb
• Friends have noticed changes in posture, locomotion and facial expression

• Symptoms are bilateral
• Minimal disability
• Posture and gait affected

• Significant slowing of body movements
• Early impairment of equilibrium on walking or standing
• Generalized dysfunction that is moderately severe

• Severe symptoms
• Can still walk to a limited extent
• Rigidity and bradykinesia
• No longer able to live alone
• Tremor may be less than earlier stages

• Cachectic stage
• Invalidism complete
• Cannot stand or walk
• Requires constant nursing care