Is Fatigue a Nursing Diagnosis? A Comprehensive Guide for Healthcare Professionals

Fatigue, a prevalent complaint in healthcare settings, is more than just feeling tired. In nursing, fatigue is recognized as a significant nursing diagnosis, representing a state of overwhelming and持续 tiredness that profoundly impacts an individual’s ability to function in their daily life. It’s characterized by a persistent sense of exhaustion, reduced physical and mental capacity, and a lack of energy that is not relieved by rest. For healthcare professionals, understanding “Is Fatigue A Nursing Diagnosis” is crucial for effective patient care and management.

It’s important to note that while the term “Fatigue” is widely used and understood, NANDA International, a leading authority in nursing diagnoses, has recently renamed this diagnosis to “Excessive Fatigue Burden“. This change reflects a move towards more precise and standardized language in nursing practice. However, due to the widespread familiarity with the term “Fatigue,” this article will primarily use this term while acknowledging the updated terminology for comprehensive understanding.

Fatigue as a nursing diagnosis differs significantly from simple tiredness. It’s a debilitating condition that can stem from various underlying causes, significantly affecting a patient’s quality of life and recovery. Recognizing fatigue as a distinct clinical entity is the first step in providing targeted and effective nursing interventions. This guide delves into the multifaceted nature of fatigue as a nursing diagnosis, exploring its causes, symptoms, assessment, and management strategies relevant to nursing practice.

Understanding the Multifaceted Causes of Fatigue

Identifying the underlying causes of fatigue is paramount in nursing assessment and care planning. Fatigue is rarely a standalone issue; it’s often a symptom of other underlying conditions or lifestyle factors. These causes can be broadly categorized into lifestyle, medical, and medication-related factors.

Lifestyle Factors Contributing to Fatigue

Lifestyle choices play a significant role in the development and exacerbation of fatigue. Addressing these factors is often the first step in managing fatigue in many patients.

• Poor Diet: An imbalanced diet lacking essential nutrients, vitamins, and minerals can lead to decreased energy production and fatigue. Irregular eating patterns and skipping meals can also contribute to fluctuations in blood sugar levels, resulting in energy dips and fatigue.
• Lack of Exercise: While counterintuitive, a sedentary lifestyle can actually worsen fatigue. Regular physical activity improves cardiovascular health, boosts energy levels, and enhances overall well-being. Conversely, lack of exercise can lead to muscle weakness and decreased stamina, contributing to feelings of fatigue.
• Excessive Alcohol Intake: Alcohol is a depressant that disrupts sleep patterns and can lead to dehydration and nutrient deficiencies, all of which contribute to fatigue. Chronic alcohol consumption can have a significant impact on energy levels and overall health.
• Substance Use: The use of illicit drugs can severely disrupt the body’s natural rhythms and energy production processes. Substance abuse often leads to nutritional deficiencies, sleep disorders, and organ damage, all contributing to profound fatigue.
• Chronic Stress: Prolonged exposure to stress, whether physical, emotional, or psychological, can deplete the body’s energy reserves. Chronic stress triggers the release of stress hormones that, over time, can lead to adrenal fatigue and a persistent feeling of exhaustion.

Medical Conditions Associated with Fatigue

Fatigue is a common symptom across a wide spectrum of medical conditions. Recognizing these conditions is essential for nurses to provide appropriate care and referrals.

• Anemia: A deficiency in red blood cells or hemoglobin reduces the oxygen-carrying capacity of the blood, leading to fatigue and weakness. Iron deficiency anemia is a common cause, but anemia can also result from chronic diseases, vitamin deficiencies, or blood loss.
• Hypothyroidism: An underactive thyroid gland slows down metabolism, resulting in decreased energy production and fatigue. Hypothyroidism can also cause weight gain, cold intolerance, and muscle weakness, further contributing to fatigue.
• Diabetes: Uncontrolled blood sugar levels in diabetes can lead to fatigue. Both hyperglycemia (high blood sugar) and hypoglycemia (low blood sugar) can disrupt energy levels and cause feelings of tiredness.
• Chronic Kidney Disease: Kidney dysfunction can lead to a buildup of toxins in the body and anemia, both of which contribute to fatigue. Patients with chronic kidney disease often experience significant and persistent fatigue.
• Heart Disease: Conditions affecting the heart’s ability to pump blood effectively can lead to reduced oxygen delivery to tissues and organs, causing fatigue and shortness of breath. Fatigue is a common symptom of heart failure and other cardiac conditions.
• Cancer: Cancer and cancer treatments, such as chemotherapy and radiation therapy, are notorious for causing fatigue. Cancer-related fatigue is often described as more severe and debilitating than typical tiredness.
• Infections: Acute and chronic infections can trigger fatigue as the body’s immune system works to fight off the infection. Common infections like influenza, mononucleosis, and urinary tract infections can cause significant fatigue. Chronic infections like HIV and hepatitis can also lead to persistent fatigue.
• Autoimmune Diseases: Conditions like rheumatoid arthritis, lupus, and multiple sclerosis, where the immune system attacks the body’s own tissues, often cause fatigue. Inflammation and chronic pain associated with these diseases contribute to feelings of exhaustion.
• Mental Health Conditions: Depression, anxiety, and other mental health disorders are strongly linked to fatigue. Mental and emotional distress can be physically draining and disrupt sleep, leading to fatigue.

Medications That Can Induce Fatigue

Many medications, while treating specific conditions, can have fatigue as a side effect. Nurses should be aware of these medications and assess for medication-related fatigue in their patients.

• Antidepressants: Certain antidepressants, particularly tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs), can cause drowsiness and fatigue, especially when starting or adjusting dosages.
• Chemotherapy Drugs: Chemotherapy agents are known to cause significant fatigue, often referred to as chemotherapy-induced fatigue (CIF). CIF can be severe and persistent, impacting patients’ quality of life during and after treatment.
• Pain Medications: Opioid pain medications and some non-opioid pain relievers can cause sedation and fatigue. Muscle relaxants, often prescribed for pain, also have fatigue as a common side effect.
• Blood Pressure Medications: Beta-blockers and diuretics, commonly used to manage high blood pressure, can sometimes cause fatigue as a side effect.
• Allergy Medications: Antihistamines, especially first-generation antihistamines, are known for their sedative effects and can cause drowsiness and fatigue.
• Muscle Relaxants: These medications, prescribed to relieve muscle spasms and pain, often have fatigue as a significant side effect due to their central nervous system depressant effects.
• Seizure or Epilepsy Medications (Anticonvulsants): Many anticonvulsant medications can cause drowsiness and fatigue as they affect brain activity.

Understanding these diverse causes of fatigue is crucial for nurses to conduct thorough assessments and develop individualized care plans. By identifying contributing factors, nurses can implement targeted interventions to alleviate fatigue and improve patient outcomes.

Alt text: Exhausted individual slumped at desk, illustrating fatigue from excessive workload and lack of rest.

Recognizing the Signs and Symptoms of Fatigue

Fatigue manifests through a variety of signs and symptoms, impacting physical, emotional, and cognitive functions. Recognizing these symptoms is vital for nurses to accurately identify fatigue as a nursing diagnosis and initiate appropriate interventions.

• Persistent Sleepiness: Feeling excessively sleepy during the day, even after adequate sleep, is a hallmark symptom of fatigue. This sleepiness is often overwhelming and interferes with daily activities.
• Irritability and Impatience: Fatigue can significantly impact mood regulation, leading to increased irritability, impatience, and emotional lability. Small frustrations may become overwhelming, and individuals may react more strongly than usual.
• General Malaise and Discomfort: A vague sense of feeling unwell, often described as malaise or general discomfort, is common in fatigue. This can include physical discomfort, achiness, and a general feeling of being unwell without specific symptoms of illness.
• Lack of Motivation: Fatigue often leads to a significant decrease in motivation and initiative. Individuals may find it difficult to start or complete tasks, even those they usually enjoy. This lack of motivation can impact work, hobbies, and social engagements.
• Muscle Weakness and Tired Legs: Physical fatigue often manifests as muscle weakness, particularly in the legs. Individuals may describe their legs as feeling heavy, tired, or weak, making physical activity challenging.
• Loss of Interest in Enjoyable Activities: Fatigue can dampen enthusiasm and lead to a loss of interest in activities that were once pleasurable. This anhedonia, or lack of enjoyment, is a significant symptom and can be indicative of both physical and emotional fatigue.
• Difficulty Concentrating: Cognitive function is often impaired by fatigue. Difficulty concentrating, focusing attention, and making decisions are common complaints. This can impact work performance, learning, and daily tasks requiring mental acuity.
• Low Energy Levels: A pervasive feeling of low energy is the defining characteristic of fatigue. Individuals may feel constantly drained, lacking the physical and mental energy to engage in typical daily activities.
• Nervousness and Anxiety: Paradoxically, fatigue can sometimes be accompanied by feelings of nervousness and anxiety. While fatigue is characterized by low energy, the underlying physiological imbalances can also trigger anxiety symptoms in some individuals.

These signs and symptoms can vary in intensity and presentation among individuals. Nurses must conduct thorough assessments to understand the specific manifestation of fatigue in each patient and tailor interventions accordingly.

Alt text: Stressed woman depicting anxiety and emotional strain, symptoms often linked to fatigue and exhaustion.

Expected Outcomes in Nursing Care for Fatigue

Setting realistic and measurable expected outcomes is crucial in nursing care planning for fatigue. These outcomes provide a framework for evaluating the effectiveness of nursing interventions and tracking patient progress. Common expected outcomes for patients experiencing fatigue include:

• Verbalization of Reduced Fatigue: Patients will report a subjective improvement in their fatigue levels. This can be measured through patient self-report scales, fatigue diaries, and verbal feedback during nursing assessments. The goal is for patients to express a noticeable and sustained reduction in their feelings of exhaustion.
• Ability to Engage in Daily Activities Independently: Patients will demonstrate an increased capacity to perform their activities of daily living (ADLs) without excessive fatigue. This includes tasks like bathing, dressing, eating, and mobility. Improved independence in ADLs signifies an increase in functional energy levels.
• Demonstration of Adequate Energy Levels: Patients will exhibit sufficient energy to complete desired activities and participate in their care. This can be observed through their engagement in therapy sessions, willingness to ambulate, and participation in social interactions. The focus is on observable improvements in energy levels during activities.
• Stable Vital Signs and Lab Values: For patients whose fatigue is related to underlying chronic conditions, maintaining stable vital signs and relevant lab values is an important outcome. This indicates that the underlying medical issues are being managed effectively, contributing to improved energy and reduced fatigue. For example, in patients with anemia, normalized hemoglobin levels would be an expected outcome.

These expected outcomes are patient-centered and focus on improving their functional capacity and quality of life. They serve as guideposts for nursing interventions and provide a basis for evaluating the effectiveness of the care plan.

Comprehensive Nursing Assessment for Fatigue

A thorough nursing assessment is the cornerstone of effective fatigue management. It involves gathering both subjective and objective data to understand the patient’s experience of fatigue, identify contributing factors, and guide intervention strategies.

1. Assess Current Activity Level Compared to Baseline:

• Rationale: Understanding the discrepancy between the patient’s current and usual activity levels helps gauge the impact of fatigue. It provides a baseline for comparison and helps determine the severity of fatigue.
• Assessment Techniques: Inquire about the patient’s typical daily routine before the onset of fatigue. Ask about their ability to perform usual activities now compared to their baseline. Determine when the fatigue started, its duration, and any patterns (e.g., time of day, after activity).

2. Assess Vital Signs:

• Rationale: Abnormal vital signs can indicate underlying physiological imbalances that contribute to fatigue. Tachycardia, hypotension, and fever can all exacerbate fatigue and may be indicative of acute or chronic conditions.
• Assessment Techniques: Measure and document heart rate, blood pressure, temperature, respiratory rate, and oxygen saturation. Be alert for deviations from the patient’s normal baseline or expected ranges.

3. Assess Lab Values:

• Rationale: Laboratory tests can reveal underlying medical conditions contributing to fatigue, such as anemia, electrolyte imbalances, or thyroid dysfunction.
• Assessment Techniques: Review recent lab results, paying particular attention to complete blood count (CBC), electrolytes, thyroid-stimulating hormone (TSH), blood glucose, and renal function tests. Identify any values outside the normal range.

4. Obtain Full Medical and Surgical History:

• Rationale: Chronic medical conditions, past surgeries, and hospitalizations can all contribute to fatigue. Identifying relevant medical history provides context for understanding the patient’s fatigue.
• Assessment Techniques: Review the patient’s medical record and interview the patient about past and present medical conditions, surgeries, hospitalizations, and significant health events.

5. Review Imaging and Cardiac Studies:

• Rationale: Imaging studies and cardiac evaluations may reveal underlying structural or functional abnormalities contributing to fatigue, such as heart failure or undiagnosed medical conditions.
• Assessment Techniques: Review reports of recent X-rays, CT scans, MRIs, echocardiograms, electrocardiograms (ECGs), and other relevant diagnostic tests.

6. Review Complete Medication List:

• Rationale: Medications are a common cause of fatigue. A thorough medication review can identify potential culprits and inform discussions about alternative medications or dosage adjustments.
• Assessment Techniques: Obtain a complete list of all medications, including prescription drugs, over-the-counter medications, herbal supplements, and vitamins. Note dosages, frequency, and timing of administration. Cross-reference medications with known side effects of fatigue.

7. Assess Need for Assistive Devices:

• Rationale: Assistive devices can help patients conserve energy and participate in activities with less fatigue. Assessing the need for and availability of assistive devices is crucial for promoting mobility and independence.
• Assessment Techniques: Observe the patient’s mobility and ability to perform activities. Ask if they currently use any assistive devices or if they feel they would benefit from using devices such as walkers, canes, or wheelchairs.

By conducting a comprehensive nursing assessment, nurses can gain a holistic understanding of the patient’s fatigue, identify contributing factors, and develop individualized care plans to address this prevalent and often debilitating symptom.

Effective Nursing Interventions for Fatigue

Nursing interventions for fatigue are multifaceted and aim to address the underlying causes, manage symptoms, and improve the patient’s functional capacity and quality of life.

1. Monitor Vital Signs and Treat Abnormalities:

• Rationale: Addressing abnormal vital signs is crucial as they can exacerbate fatigue and indicate underlying medical instability.
• Interventions: Regularly monitor vital signs (heart rate, blood pressure, temperature, respiratory rate, oxygen saturation). Report and treat abnormal values according to physician orders and established protocols. For example, manage fever with antipyretics, address tachycardia or hypotension per orders.

2. Administer Supplemental Oxygen Therapy as Needed:

• Rationale: Hypoxia (low oxygen levels) can cause significant fatigue and shortness of breath, especially during activity. Supplemental oxygen can improve oxygenation and reduce fatigue related to respiratory insufficiency.
• Interventions: Assess oxygen saturation levels, particularly during and after activity. Administer supplemental oxygen as prescribed to maintain adequate oxygenation, especially during activities of daily living or ambulation.

3. Monitor Lab Work and Treat Abnormal Values:

• Rationale: Addressing abnormal lab values, such as anemia or electrolyte imbalances, is essential to correct underlying physiological causes of fatigue.
• Interventions: Regularly monitor relevant lab values (e.g., CBC, electrolytes, renal function). Administer treatments as ordered by the provider to correct abnormal values, such as blood transfusions for severe anemia or electrolyte replacement therapy.

4. Provide Appropriate Assistive Devices:

• Rationale: Assistive devices can reduce the energy expenditure required for mobility and activities, thereby lessening fatigue and promoting independence.
• Interventions: Assess the patient’s need for assistive devices. Provide and ensure proper use of devices such as walkers, canes, wheelchairs, or adaptive equipment for ADLs. Ensure devices are readily available and properly fitted.

5. Develop an Activity Plan:

• Rationale: A structured activity plan helps patients gradually increase their activity levels without exacerbating fatigue. It promotes pacing, energy conservation, and gradual reconditioning.
• Interventions: Collaborate with the patient to develop a personalized activity plan. Start with short, manageable activities and gradually increase duration and intensity as tolerated. Incorporate rest periods, activity clustering (grouping activities together to minimize energy expenditure), and pacing techniques. Educate the patient on energy conservation strategies.

6. Discuss Physical Therapy and Cardiac Rehabilitation:

• Rationale: Physical therapy and cardiac rehabilitation programs provide structured exercise and rehabilitation to improve strength, endurance, and reduce fatigue, particularly for patients recovering from illness or surgery or those with chronic conditions.
• Interventions: Discuss the potential benefits of physical therapy and/or cardiac rehabilitation with the ordering provider. Obtain referrals as appropriate. Encourage patient participation in recommended programs.

7. Treat Underlying Causes of Fatigue:

• Rationale: Addressing and managing the underlying medical conditions or lifestyle factors contributing to fatigue is paramount for long-term fatigue reduction.
• Interventions: Work collaboratively with the healthcare team to ensure appropriate treatment of underlying medical conditions (e.g., anemia, hypothyroidism, heart failure, infections). Encourage lifestyle modifications, such as dietary changes, exercise programs, stress management techniques, and smoking cessation, as appropriate.

8. Educate Patient on Lifestyle Habits and Self-Care:

• Rationale: Patient education empowers individuals to take an active role in managing their fatigue through lifestyle modifications and self-care strategies.
• Interventions: Educate the patient about lifestyle factors that contribute to fatigue (diet, exercise, sleep hygiene, stress management). Provide guidance on healthy eating habits, regular physical activity, stress reduction techniques, and establishing a consistent sleep schedule. Discuss energy conservation techniques and the importance of self-care practices.

By implementing these comprehensive nursing interventions, nurses can effectively address fatigue, improve patient outcomes, and enhance their quality of life.

Alt text: Nurse explaining care plan to patient, emphasizing patient education and teamwork in fatigue management.

Nursing Care Plans: Examples for Managing Fatigue

Nursing care plans provide a structured framework for organizing and delivering patient care. Here are examples of nursing care plans addressing fatigue in different contexts.

Care Plan #1: Fatigue Related to Caregiving Responsibilities

Diagnostic Statement: Fatigue related to caregiving responsibilities as evidenced by daytime sleepiness and reported lack of energy.

Expected Outcomes:

• Patient will verbalize a reduction in fatigue, reporting increased energy levels by [date].
• Patient will demonstrate energy-conservation techniques in daily activities by [date].

Assessment:

1. Assess the description of fatigue: Timing, severity, relationship to activities, alleviating/aggravating factors. Rationale: Individualized fatigue experience informs activity planning.
2. Assess feelings of fatigue related to caregiving: Feelings of burnout, anxiety, depression. Rationale: Caregiver burnout and emotional responses can exacerbate fatigue.

Interventions:

1. Encourage a weekly 24-hour fatigue and activity log: Rationale: Identifies activities causing excessive energy expenditure for activity planning.
2. Assist in developing a daily schedule of rest and activity: Rationale: Balances work and rest to perform responsibilities without excessive fatigue.
3. Minimize environmental stimuli during rest and sleep: Rationale: Uninterrupted rest/sleep is crucial to reduce fatigue. Noise, light, and distractions inhibit relaxation.
4. Teach energy conservation skills: Delegating tasks, setting priorities, clustering care, assistive devices. Rationale: Organization and time management conserve energy and reduce fatigue. Occupational therapy can reinforce techniques and provide assistive devices.

Care Plan #2: Fatigue Related to Iron Deficiency Anemia

Diagnostic Statement: Fatigue related to iron deficiency anemia, as evidenced by inability to maintain usual routines and pale conjunctiva.

Expected Outcomes:

• Patient will verbalize a reduction in fatigue, reporting ability to perform usual routines by [date].
• Patient will achieve normalized CBC, hemoglobin, iron, and ferritin levels within [timeframe].

Assessment:

1. Assess ability to perform ADLs: Rationale: Fatigue limits ADL performance. Knowing capability identifies areas needing assistance.
2. Assess precipitating factors of anemia: Medical history, diet history, medications. Rationale: Correcting anemia resolves fatigue. Addressing root causes is vital.
3. Obtain diet history: Iron intake, dietary habits. Rationale: Iron deficiency anemia is a nutritional problem. Diet history identifies deficiencies.

Interventions:

1. Plan a balanced meal with the patient: Focus on iron-rich foods. Rationale: Balanced nutrition provides energy resources, addressing nutrient deficiencies.
2. Administer ferrous sulfate/iron supplements as prescribed: Rationale: Iron supplements manage iron-deficiency anemia by supporting hemoglobin production.
3. Encourage appropriate exercise programs (as tolerated): Rationale: Exercise builds endurance and reduces fatigue, but extreme exercise can worsen iron deficiency.
4. Educate on energy conservation and time management strategies: Rationale: Organization and time management conserve energy and prevent fatigue.

Care Plan #3: Fatigue Related to Chemotherapy

Diagnostic Statement: Fatigue related to chemotherapy as evidenced by lethargy and reported lack of energy during treatment cycles.

Expected Outcomes:

• Patient will verbalize increased energy and improved vitality during non-chemotherapy weeks.
• Patient will explain their energy conservation plan to offset fatigue by [date].

Assessment:

1. Assess for other symptoms enhancing fatigue: Pain, insomnia, anemia, emotional distress, electrolyte imbalance, nausea, vomiting, diarrhea, depression. Rationale: Cancer-related fatigue is multifactorial and exacerbated by other symptoms.
2. Review medications for side effects: Drug interactions, adverse effects. Rationale: Aging cancer patients are susceptible to drug-related fatigue.
3. Conduct a comprehensive fatigue assessment: Severity, frequency, timing, associated activities, impact on ADLs, mood, sleep patterns, energy levels. Rationale: Provides a baseline for planning rest/activity schedules.
4. Assess motivation and willingness to adopt fatigue-management behaviors: Cognitive behavioral therapy, exercise, counseling. Rationale: Motivation is key for successful fatigue management.

Interventions:

1. Encourage patient to express feelings about fatigue: Causes, coping behaviors, impact on life. Rationale: Uncovers potential causes and interventions, promotes hope.
2. Encourage activity journal: Track fatigue symptoms, patterns, and impact on daily activities. Rationale: Promotes self-awareness and a sense of control over fatigue.
3. Collaborate with primary care provider: Referrals to physical therapy, aerobic exercise programs. Rationale: Exercise, especially aerobic, reduces cancer-related fatigue when appropriate.
4. Encourage complementary therapies: Guided imagery, massage therapy, mindfulness, acupressure. Rationale: These therapies have shown promise in managing chronic fatigue.

These care plan examples demonstrate the application of the nursing process to address fatigue in diverse patient populations and clinical scenarios. They highlight the importance of individualized assessment, outcome identification, and tailored interventions to effectively manage fatigue and improve patient well-being.

Conclusion: Fatigue as a Critical Nursing Diagnosis

Fatigue is a significant and multifaceted symptom that warrants careful consideration as a nursing diagnosis. Understanding “is fatigue a nursing diagnosis” is fundamental for nurses to provide holistic and patient-centered care. By recognizing fatigue as a distinct clinical entity, nurses can move beyond simply acknowledging tiredness and delve into the underlying causes, contributing factors, and effective management strategies.

This guide has explored the diverse causes of fatigue, ranging from lifestyle factors and medical conditions to medication side effects. Recognizing the signs and symptoms of fatigue, conducting comprehensive assessments, and implementing targeted nursing interventions are essential components of effective fatigue management. Nursing care plans, tailored to individual patient needs and circumstances, provide a structured approach to addressing fatigue and promoting positive patient outcomes.

In conclusion, fatigue is not merely a subjective complaint but a critical nursing diagnosis that demands thorough assessment, thoughtful planning, and compassionate intervention. By embracing a comprehensive understanding of fatigue, nurses can significantly improve the lives of patients struggling with this pervasive and debilitating symptom.

References

1. Ackley, B.J., Ladwig, G.B.,& Makic, M.B.F. (2017). Nursing diagnosis handbook: An evidence-based guide to planning care (11th ed.). Elsevier.
2. Carpenito, L.J. (2013). Nursing diagnosis: Application to clinical practice (14th ed.). Lippincott Williams & Wilkins.
3. Cleveland Clinic (2020). Fatigue. https://my.clevelandclinic.org/health/symptoms/21206-fatigue
4. Doenges, M.E., Moorhouse, M.F., & Murr, A.C. (2019). Nursing care plans: Guidelines for individualizing client care across the life span (10th ed.). F.A. Davis Company.
5. Gulanick, M. & Myers, J.L. (2014). Nursing care plans: Diagnoses, interventions, and outcomes (8th ed.). Elsevier.
6. Herdman, T. H., Kamitsuru, S., & Lopes, C. (Eds.). (2024). NANDA-I International Nursing Diagnoses: Definitions and Classification, 2024-2026. Thieme. 10.1055/b-0000-00928
7. Mayo Clinic. (2020). Fatigue. https://www.mayoclinic.org/symptoms/fatigue/basics/causes/sym-20050894
8. O’Connell, K. (2020). Causes of fatigue and how to manage it. https://www.healthline.com/health/fatigue
9. Turner, J., Parsi, M.& Badireddy, M. (2022). Anemia. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK499994/