Last updated Jan. 19, 2022, by Marisa Wexler, MS
Fact-checked by Ana de Barros, PhD
Parkinson’s disease is a neurological disorder characterized by the impairment and death of dopamine-producing nerve cells in the brain. The loss of these cells leads to problems with normal signaling in the brain. As a result, patients may experience a number of motor (movement-related) and non-motor symptoms.
Parkinson’s disease is perhaps most famous for the motor symptoms it causes. For example, most patients at some point will experience resting tremors, when parts of the body shake uncontrollably while they are at rest. Indeed, slight tremors in the fingers, hand, or foot on one side of the body can be an early sign of the disease.
Patients also may experience bradykinesia (abnormally slow movements), unwanted rapid movements, or freezing. Rigidity and abnormal muscle tone can develop, and it is common for people with Parkinson’s to experience difficulty walking and keeping their balance. Motor symptoms also often cause patients to have unusually small writing, called micrographia.
Uncontrolled movements — referred to as dyskinesia — are not a symptom of Parkinson’s itself, but are often associated with the disease because they are a common side effect of the most common medicines used to manage Parkinson’s.
In addition to the motor symptoms that characterize Parkinson’s, the disease also can cause many problems that are not related to movement. For example, loss of the sense of smell is often an early symptom of the disease.
Patients often experience difficulties with cognition and/or changes in mood, which may include depression, anxiety, and irritability. Some people with the disorder may experience psychosis — sensing things that aren’t there (hallucinations) and/or believing something with no basis in reality (delusions). Uncontrolled bouts of laughing or crying, called the pseudobulbar affect, may develop.
Sleep problems such as insomnia, nightmares, emotional dreams, and restless sleep are common among people with Parkinson’s, and patients often experience fatigue and sleepiness during the daytime. Parkinson’s also may cause constipation or urinary problems, excessive sweating, or sexual problems like erectile dysfunction.
Parkinson’s News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.