This is a progressive disorder of the nervous system which is affecting the movement. Parkinson’s disease develops gradually and in some cases, it starts with a barely noticeable tremor in just one hand. The tremor is the most well – known sign of Parkinson’s disease. This disorder is commonly causing slowing or stiffness of movement. When someone has early stages of Parkinson’s disease, then his or her face can show a little or no expression or his/her arms may not swing when he/she walks. Also the speech can become slurred or soft. As this condition progresses over time, the symptoms of Parkinson’s disease are worsening. This disease cannot be cured but you can take medications which can improve the symptoms. There are rare cases when doctor can suggest surgery to regulate certain regions of the brain and to improve the symptoms .
Parkinson’s disease Symptoms
Symptoms: The signs and symptoms of Parkinson’s disease can vary from person to person. The early signs of this disease can be mild and they can go unnoticed. The symptoms of Parkinson’s disease often begin on one side of the body and they remain worse on that side and even after the symptoms begin to affect the both sides. Here are some signs and symptoms of Parkinson’s disease:
- Writing changes: When you have this disease, then it can become hard for you to write and your writing can appear small.
- Speech changes: You can have speech problems that are caused by this disease. You can speak quickly, softly, slur or hesitate before you speak. Also your speech can be more of a monotone rather than with the usual inflections. 
- Loss of automatic movements: When someone has this disease, then he or she can have a decreased ability to perform unconscious movements, including smiling, blinking or swinging his/her arms when he or she are walking. 
- Impaired posture and balance: You can have balance problems or your posture may become stooped as a result of this disease.
- Rigid muscles: The muscle stiffness can happen in any part of the body. Stiff muscles can cause you a pain and can limit the range of motion.
- Slowed movement (bradykinesia): As this disease progresses, it can reduce the ability to move and slow your movement which is making the simple tasks time – consuming and difficult. You can find it difficult to get out of a chair or your steps may become shorter when you walk. You can drag your feet as you try to walk which is making difficult for you to move. 
- Tremor: Tremor is the term which is used for shaking. It begins in a limb, often your fingers or hands. You can notice pill – rolling tremor (this is a back – and – forth rubbing of the thumb and forefinger). When your hand is relaxed or at rest, then you can have a tremor which is one of the main characteristics of Parkinson’s disease. 
Causes: When someone has this disease, then certain neurons (nerve cells) in the brain gradually break down or die. Many of them are caused by loss of dopamine (neurons which produce a chemical messenger in the brain). When the dopamine levels decrease, then it is causing abnormal brain activity which is leading to the signs of Parkinson’s disease. It is not known the cause for Parkinson’s disease but there are some factors which can play a role in it, such as
- Environmental triggers: It is known that the exposure to certain environmental factors or toxins can increase the risk of later Parkinson’s disease, but the risk of it is relatively small.
- Your genes: There are some studies in which are said that specific genetic mutations can cause Parkinson’s disease. These genetic mutations are uncommon except with many family members that are affected by this disease. But there are certain gene variations that can increase your risk of Parkinson’s disease but they have a small risk of this disease for each of these genetic markers. 
Parkinson’s disease Complications
Complications: This disease is often accompanied by additional problems which can be treatable, such as
- Bladder problems
- Sleep problems and sleep disorders 
- Swallowing problems
- Depression and emotional changes 
- Thinking difficulties
 Lee DJ, Dallapiazza RF, De Vloo P, Lozano AM. Current surgical treatments for Parkinson’s disease and potential therapeutic targets. Neural Regeneration Research. 2018;13(8):1342-5.
 Skodda S, Gronheit W, Mancinelli N, Schlegel U. Progression of voice and speech impairment in the course of Parkinson’s disease: A longitudinal study. Parkinson’s Disease. 2013.
 Mazzoni P, Shabbott B, Cortes JC. Motor control abnormalities in Parkinson’s disease. Cold Spring Harbor Perspectives in Medicine. 2012;2(6):a009282.
 Tarakad A, Jankovic J. Essential tremor and Parkinson’s disease: Exploring the relationship. Tremor and Other Hyperkinetic Movements. 2018;8:589.
 Shihabuddin LS, Brundin P, Greenamyre JT, et al. New frontiers in Parkinson’s disease: From genetics to the clinic. Journal of Neuroscience. 2018;38(44):9375-82.
 Loddo G, Calandra-Buonaura G, Sambati L, et al. The Ttreatment of sleep disorders in Parkinson’s disease: From research to clinical practice. Frontiers in Neurology. 2017;8:42.
 Marsh L. Depression and Parkinson’s disease: Current knowledge. Current Neurology and Neuroscience Reports. 2013;13(12):409.