Parkinson’s disease (PD) is a progressive neurological disorder that primarily affects movement. It arises from the loss of dopamine-producing neurons in the brain, leading to characteristic motor symptoms. There is currently no definitive at-home test for Parkinson’s disease; only a medical professional, specifically a neurologist, can provide a diagnosis. This information provides tools for recognizing and systematically monitoring subtle signs, which is valuable for early intervention. Tracking symptoms can inform a physician and help determine if a formal evaluation is necessary.
Recognizing Subtle Early Symptoms
PD is often preceded by non-motor symptoms that can appear years before movement difficulties begin. Loss of the sense of smell (anosmia) is a common early symptom, often dismissed as allergies. Chronic constipation, unexplained by diet or medication, is another frequent early indicator, reflecting autonomic nervous system issues.
Sleep disturbances, particularly Rapid Eye Movement (REM) sleep behavior disorder (RBD)—where individuals physically act out vivid dreams—can precede motor symptoms by a decade or more. These non-motor changes are vague and not exclusive to PD, but their combined presence raises suspicion. Motor symptoms, when they emerge, are often unilateral, affecting one side of the body more than the other.
Early motor changes are frequently subtle and may be mistaken for normal aging. A slight resting tremor in a finger, hand, or chin, which disappears during purposeful movement, is a common initial sign. Micrographia, a reduction in handwriting size, is another early change. Reduced arm swing on one side while walking or a sense of stiffness in a limb are also physical manifestations.
Simple Screening Activities to Monitor Symptoms
Since a formal diagnosis requires a physician, structured self-monitoring helps track subtle changes over time. A simple activity is a weekly handwriting check: write the same short sentence or phrase on a standardized, dated sheet of paper. Keeping these samples allows one to visually track if the writing consistently becomes smaller or more crowded, indicating potential micrographia.
Monitoring the speed and amplitude of repetitive movements helps screen for bradykinesia. Rapidly tap the index finger and thumb together for 30 seconds, observing for any decay in the speed or size of the movement. A healthy person maintains a steady pace, but someone with emerging bradykinesia may slow down and make smaller movements.
Observing gait and posture is a useful screening activity, often requiring a family member’s help. They should look for reduced arm swing, especially on one side, or a tendency toward a slightly stooped posture or shuffling walk. Additionally, a mirror check can help monitor for changes in facial expression, often called “masking” or hypomimia, which involves a reduced blink rate or decreased capacity to display emotion. These monitoring activities provide objective data points helpful during a clinical consultation.
When to Seek Professional Evaluation
The decision to seek professional evaluation should be based on the persistence and combination of observed symptoms, not a single, isolated sign. The most significant trigger is the presence of unilateral symptoms, such as a tremor or stiffness affecting one side of the body noticeably more than the other. Any symptom, motor or non-motor, that begins to interfere with daily activities, such as dressing, eating, or walking, warrants medical attention.
It is appropriate to first consult a primary care physician (PCP), who can perform an initial assessment and rule out other causes, such as medication side effects or essential tremor. If the PCP suspects a movement disorder, they will provide a referral to a neurologist specializing in movement disorders. Before the appointment, compile a symptom journal detailing when symptoms started, how frequently they occur, and what makes them better or worse. A complete list of all current medications is also necessary, as some drugs can mimic Parkinson’s symptoms.
What a Neurologist Does to Confirm Diagnosis
A diagnosis of Parkinson’s disease is primarily clinical, based on a detailed medical history and a comprehensive neurological examination. The neurologist observes the patient’s gait, posture, and facial expressions while testing reflexes, balance, and muscle tone for rigidity. They look for the cardinal motor symptoms: slowness of movement (bradykinesia), rest tremor, and rigidity.
The neurologist often uses a standardized tool, such as the Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), to formally assess symptom severity. This scale provides a baseline score to track disease progression and treatment effectiveness. A positive response to levodopa, a medication that increases dopamine levels, can also support a clinical diagnosis.
If the diagnosis remains uncertain or symptoms are mild, the neurologist may order a Dopamine Transporter Scan (DaTscan). This imaging test uses a radioactive tracer that binds to dopamine transporters, allowing a SPECT scanner to visualize their density. A DaTscan cannot differentiate PD from other parkinsonian syndromes, but it helps distinguish it from conditions like essential tremor, where scan results are normal.