Fatigue in Parkinson’s Disease: Causes, Prevalence, and Practical Management

Fatigue is a frequent and burdensome non‑motor symptom of Parkinson’s disease (PD), often described as a persistent sense of tiredness or lack of energy that is out of proportion to activity levels and not fully relieved by rest. ^[1] Fatigue can worsen daily function and quality of life, and many people with PD notice it especially later in the day. ^[1]

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How Common Is Fatigue in PD?

Fatigue is one of the most common non‑motor complaints in PD and is linked with reduced activity and poorer quality of life. ^[2] It affects a large proportion of people living with PD, often early in the disease course, and tends to worsen with progression. ^[3] Many individuals report both mental (cognitive) and physical fatigue, which can feel different from pre‑PD fatigue. ^[3]

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What Causes Fatigue in PD?

Fatigue in PD is multifactorial, meaning several mechanisms can contribute at the same time.

• Brain chemical changes (dopamine and others): PD involves low brain dopamine, and fatigue may relate to changes in dopamine and other neurotransmitter systems that affect attention, motivation, and motor control. ^[4] PD subjects show abnormalities across attention networks, suggesting neurotransmitter targets may help mental fatigability. ^[2]

• Sleep disturbances: REM sleep behavior disorder, difficulty turning in bed, and restless legs can fragment sleep, leading to daytime sleepiness and fatigue. ^[5] Disrupted sleep can cause excessive daytime fatigue and worsen other symptoms. ^[5]

• Autonomic issues and other non‑motor symptoms: Constipation, orthostatic hypotension (blood pressure drops on standing), and pain are common in PD and can compound fatigue. ^[1] These non‑motor symptoms often coexist with depression or anxiety, which may also contribute to low energy. ^[6]

• Depression and mood symptoms: While many people with PD who have fatigue are not depressed, depression and anxiety can still be contributors and should be screened and treated. ^[3] Mood disorders are recognized non‑motor features of PD and may accompany fatigue. ^[6]

• Physical and mental fatigability: Beyond the feeling of tiredness (subjective fatigue), PD is associated with measurable increases in physical fatigability (e.g., force generation, finger tapping) and mental fatigability (decline in attention over time). ^[2] This helps explain why tasks may feel increasingly effortful as the day or activity progresses. ^[2]

• Other medical causes (worth ruling out): Fatigue can also result from anemia, thyroid, liver, kidney disease, untreated pain, infections, and sleep apnea, which should be evaluated if symptoms are significant or change abruptly. ^[7] Sleep apnea and other sleep disorders are well‑known contributors to daytime fatigue. ^[8]

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How Fatigue Presents: Physical vs. Mental

PD‑related fatigue can be experienced as:

• Subjective fatigue: A persistent sense of being tired or weary (physical or mental), often captured by questionnaires like the Fatigue Severity Scale or Multidimensional Fatigue Inventory. ^[2]

• Fatigability: A process of becoming tired during tasks, seen as declining performance with sustained physical effort or prolonged attention, measurable in lab tasks such as force generation and reaction‑time tests. ^[2]

People with PD often report both types and may notice that exercise can paradoxically feel helpful for fatigue compared with typical physical fatigue in non‑PD individuals. ^[3]

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Recommended Strategies to Manage Fatigue

There is no single proven cure for PD‑related fatigue, but a combination of lifestyle, sleep optimization, targeted treatment of co‑existing conditions, and cautious medication trials may help.

1) Identify and Treat Reversible Contributors

• Sleep disorders: Address REM sleep behavior disorder, insomnia, or restless legs to improve sleep quality and daytime energy. ^[5]
• Orthostatic hypotension: If lightheadedness or “faint feeling” on standing is present, managing blood pressure drops may reduce fatigue. ^[1]
• Constipation, pain, urinary symptoms: Treating these common non‑motor problems can lessen overall fatigue burden. ^[1]
• Depression/anxiety: Screen and treat mood symptoms, which often travel with fatigue in PD. ^[6]
• General medical causes: Check for anemia, thyroid, kidney, liver issues, infection, untreated pain, and sleep apnea. ^[7] Sleep apnea and other sleep disorders are frequent fatigue drivers that warrant assessment and treatment. ^[8]

2) Optimize PD Motor Therapy Thoughtfully

Adjusting PD medications to smooth motor “on/off” fluctuations and reduce nighttime symptoms may indirectly help energy, although fatigue does not reliably improve with motor symptom treatment alone. ^[3] Dopamine‑targeted therapy is central to PD care, but it does not consistently resolve fatigue. ^[4] Exercise and physical therapy focused on balance and flexibility can improve overall function and mood, which may help with daytime energy. ^[9]

3) Non‑Pharmacologic Approaches

• Structured exercise: Regular, moderate activity can improve strength, mood, and perceived energy, and many people with PD feel exercise helps their fatigue. ^{[9] [3]}
• Energy conservation and pacing: Prioritize tasks, plan rests, and schedule demanding activities for times of higher energy (often morning). ^[10]
• Sleep hygiene: Keep consistent sleep/wake times, limit late caffeine, and create a restful environment to reduce nighttime disruptions that feed daytime fatigue. ^[5]
• Supportive therapies: Massage, relaxation techniques, and multidisciplinary rehabilitation (physical, occupational, speech therapy) can ease non‑motor symptoms and reduce overall symptom burden. ^[11]

Importantly, despite these commonsense strategies, research to date finds insufficient high‑quality evidence to endorse any single non‑drug intervention as definitively effective for PD fatigue, underscoring the need for personalized, multi‑modal plans. ^[12]

4) Pharmacologic Options (Evidence and Caution)

Evidence for medications is mixed and limited:

• Levodopa: May improve physical fatigability measures in some lab settings, but real‑world subjective fatigue often persists. ^[2]
• Modafinil: Has improved physical fatigability in some studies but failed to consistently help subjective fatigue. ^{[2] [3]}
• Methylphenidate: Reported benefit for subjective physical fatigue in one study and used pragmatically by some clinicians with careful screening for cardiac/psychiatric risks. ^{[2] [3]}

Overall, current trials do not provide strong, consistent evidence to support a particular drug for PD fatigue, and treatment should be individualized with risk‑benefit discussions. ^[12] Any stimulant‑type medication should be considered cautiously, tailored to comorbidities, and monitored closely. ^[3]

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Practical Day‑to‑Day Tips

• Plan and pace: Break tasks into shorter blocks with scheduled rest periods to avoid “energy crashes.” ^[10]
• Move regularly: Gentle, regular exercise (walking, stretching, cycling, tai chi) can boost energy and mood; start slowly and build up as tolerated. ^[9]
• Sleep first: Improve sleep quality by addressing nighttime motor symptoms, leg discomfort, and REM sleep behavior disorder. ^[5]
• Hydration and fiber: Adequate fluids and fiber support bowel health, which can reduce the drain of constipation. ^[9]
• Team‑based care: Physical therapy for balance and flexibility, occupational therapy for energy‑saving strategies at home, and speech therapy for swallowing/speech difficulties can all ease daily strain. ^{[9] [11]}

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Key Takeaways

• Fatigue is common and multifactorial in PD, frequently linked with sleep problems, autonomic symptoms, mood, and both mental and physical fatigability. ^{[1] [5] [6] [2]}
• Prevalence is high, and fatigue strongly impacts quality of life even early in the disease. ^{[2] [3]}
• Management is individualized, focusing first on reversible contributors (sleep, mood, autonomic symptoms, medical comorbidities), then on exercise, pacing, sleep hygiene, and cautious medication trials where appropriate. ^{[5] [7] [8] [9] [12] [3]}

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Quick Reference Table: Contributors and Actions

Potential contributor	What to look for	Suggested actions
Sleep disruption (REM behavior disorder, restless legs, insomnia)	Acting out dreams, difficulty turning, leg discomfort, fragmented sleep	Sleep hygiene; treat RBD/restless legs; review PD meds affecting sleep; consider sleep study if needed. [5]
Orthostatic hypotension	Lightheadedness or “blackouts” on standing	Hydration, slow position changes, review meds; discuss targeted therapies with clinician. [1]
Constipation, pain, urinary issues	Straining, abdominal discomfort, muscle/joint pain, frequent urination	Fiber/fluid intake; bowel regimen; pain strategies; urology input as needed. [1] [9]
Mood symptoms (depression/anxiety)	Low mood, loss of interest, worry	Screen and treat; therapies and/or medications as appropriate. [6]
General medical causes	Anemia, thyroid, kidney/liver issues, infection, sleep apnea	Appropriate labs, medical workup, and targeted treatment. [7] [8]
PD‑related fatigability	Increasing effort with tasks, attention drop‑off	Task pacing, rest breaks, structured exercise, cognitive strategies. [2] [9]

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If you’d like help tailoring these strategies to your situation, you can share your typical day, sleep pattern, medications, and any symptoms like dizziness or pain, and we can build a practical plan together.