Parkinson’s disease is a continuously progressive neurodegenerative disorder that affects the nervous system, particularly the brain’s substantia nigra, responsible for dopamine production. It constitutes the basal ganglia circuit. The basal ganglia circuit is responsible for voluntary movements, and the lack of dopamine affects how you move.
Parkinson’s disease does not have a specific cause, but scientists have linked several risk factors such as age, gender, environmental factors, genetics, and even head trauma. The following early warning signs of Parkinson’s disease are not easily noticeable, especially if they occur irregularly:

1. Tremors
Tremors are the most prominent symptoms at the onset of Parkinson’s disease. A person will start experiencing slight twitches or shaking in their limbs, often in the fingers that will only be noticeable to them at the beginning. Initially, only one side of the body is affected by the shakes. However, as the disease progresses, the shakes become more widespread in the body, and other people will also start noticing the shakes.

2. Rigid muscles and stiffness
The inability of your muscles to relax is typically known as rigidity. Rigid muscles and stiffness is a common occurrence in healthy people but eventually goes away. However, with Parkinson’s disease the rigidity and stiffness of the muscles progressively become prevalent. It will also be coupled with pains and aches in the affected muscles, limiting one’s scope of movement. The stiffness is caused by the impairment of substantia nigra neurons responsible for movement in the body. One will begin to experience jerkier motions of their limbs, leading to uncoordinated movement.

3. Slower movement and decreased mobility
Slow movement and decreased mobility, also known as bradykinesia, is one of the primary symptoms of Parkinson’s disease. It is caused by the brain’s inability to effectively transmit instructions to the appropriate parts of the body. Unfortunately, this symptom is unpredictable and can quickly degenerate to disability. An individual might require help in doing simple tasks like dressing, bathing, getting out of bed, and getting up from a chair.

4. Decreased facial expression
The degeneration of substantia nigra, affects the control of muscle movement throughout the body, including facial muscles. The facial muscles lose the ability to express emotion, a condition known as hypomimia or facial masking. The failure of facial motor control causes a disconnect between one’s thoughts, feelings, and speech with their facial expressions. Often a person who has Parkinson’s disease will have a blank expression despite how they are feeling.

5. Arms don’t swing when walking
Decreased arm swing occurs in the very early stages of Parkinson’s disease and is one of the most commonly reported motor dysfunction in people suffering from the disease. Arm and leg movements when walking are neurally connected. Due to degeneration of the brain function that controls this network, people with Parkinson’s cannot swing arms in concert with the legs while walking. Researchers from Penn State University came up with an arm swing test which they noted is a cheaper method of diagnosing Parkinson’s disease than a brain test. The arm swing test is crucial because it can help in the early diagnosis of a patient to receive intervention sooner to slow down the disease’s progress.