Parkinson’s disease is a degenerative disorder that affects the nervous system, primarily the movement functions. The disease is characterized by a gradual loss of dopamine-producing neurons in the brain, leading to a reduction in dopamine levels.

This chemical deficit is responsible for most of the motor symptoms of Parkinson’s disease, such as tremors, stiffness, and slow movement. Although these symptoms are the most well-known, Parkinson’s disease can affect a wide range of functions in the body, including cognition, mood, and sleep.

1. Tremors

The most common symptom of Parkinson’s disease is tremors, which typically start in one hand or arm and eventually involve the other side of the body.

Tremors usually occur at rest and may disappear during movement but can worsen when the person is stressed or anxious. In some cases, tremors can also affect the head, jaw, and legs.

2. Rigidity

Rigidity is another common symptom of Parkinson’s disease. It is characterized by stiffness in the muscles, making it difficult for the person to move or perform daily activities.

Rigidity can also cause pain, especially in the neck, shoulders, and back.

3. Bradykinesia

Bradykinesia refers to slowness of movement, which can affect different parts of the body. People with Parkinson’s disease may have difficulty initiating movements, and their movements may be unusually small or slow.

This symptom can affect daily activities such as walking, dressing, or eating.

4. Postural instability

Postural instability refers to difficulty maintaining balance and posture. It can cause falls, which are a common cause of injury in people with Parkinson’s disease.

Postural instability is due to a combination of motor and non-motor symptoms, such as rigidity, impaired proprioception (the ability to sense body position), and cognitive impairment.

5. Dyskinesias

Dyskinesias are involuntary movements that can occur in people who have been treated with levodopa, a medication commonly used to manage Parkinson’s disease.

Dyskinesias can take different forms, such as chorea (unpredictable, jerky movements), dystonia (abnormal postures), or ballism (flinging movements). Dyskinesias can be disabling and affect the quality of life of the person with Parkinson’s disease.

6. Micrographia

Micrographia, also called small handwriting, is a symptom that affects handwriting and related activities.

People with Parkinson’s disease may find it difficult to write legibly, and their letters may become progressively smaller and harder to read. Micrographia is due to bradykinesia and rigidity, which impair the fine motor control needed for handwriting.

7. Freezing

Freezing is a sudden and temporary inability to move, usually during walking or other rhythmic movements. Freezing can last for a few seconds or minutes and can be triggered by stress, distraction, or narrow spaces.

Freezing is due to a combination of motor and non-motor symptoms, such as bradykinesia, rigidity, and executive dysfunction.

8. Sleep disturbances

Sleep disturbances are common in Parkinson’s disease and can affect both the quality and quantity of sleep.

Sleep disturbances can take different forms, such as insomnia (difficulty falling or staying asleep), sleep apnea (interrupted breathing during sleep), or REM sleep behavior disorder (acting out dreams). Sleep disturbances are due to a combination of motor and non-motor symptoms, such as nocturnal rigidity, excessive daytime sleepiness, and depression.

9. Cognitive impairment

Cognitive impairment is a common non-motor symptom of Parkinson’s disease, affecting up to 80% of people with the disease. Cognitive impairment can take different forms, such as memory loss, executive dysfunction, and visual-spatial impairment.

Cognitive impairment can affect daily activities, such as driving, working, or managing finances.

10. Mood disorders

Mood disorders, such as depression and anxiety, are common in Parkinson’s disease. Mood disorders can affect the quality of life of the person with the disease and can also worsen other symptoms, such as bradykinesia and rigidity.

Mood disorders are due to a combination of motor and non-motor symptoms, such as the loss of dopamine and the disruption of the serotonin and noradrenaline systems.