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ULY CLINIC

9 Septemba 2025, 06:06:21

Fatigue

Fatigue is a subjective sensation of excessive tiredness, lack of energy, or exhaustion, often accompanied by a strong desire to rest or sleep. It is distinct from muscle weakness but may coexist with it.

Pathophysiology

Fatigue reflects hypermetabolic or hypometabolic states where cellular energy supply is inadequate due to rapid depletion of nutrients, impaired replacement mechanisms, hormonal insufficiency, or insufficient intake/metabolism of nutrients. Both physical and psychological factors contribute.

Signs and Symptoms

Excessive tiredness or sleepiness
Decreased physical or mental performance
Difficulty initiating or sustaining activity
Associated somatic or cognitive complaints depending on underlying cause

Clinical Assessment

Assessment focuses on pattern, duration, aggravating or relieving factors, associated symptoms, and risk factors for underlying systemic or psychological disorders.

History

Onset, duration, pattern, and progression of fatigue
Relation to activity and rest
Recent infections or stressors
Nutritional habits and appetite
Drug, alcohol, and toxin exposure
Past medical and psychiatric history, family history

Physical Examination

General appearance: posture, grooming, expression
Signs of systemic illness: pallor, weight changes, edema, muscle wasting
Neurological evaluation if indicated: mental status, attention, and cognitive function

Medical Causes of Fatigue

Cause	Onset / Pattern	Distinguishing Features
AIDS	Gradual, chronic	Fatigue, fever, night sweats, weight loss, diarrhea, opportunistic infections
Adrenocortical insufficiency	Gradual, worsening	Fatigue, weakness, weight loss, GI disturbances, hyperpigmentation, orthostatic hypotension
Anemia	Gradual, post-exertion	Pallor, tachycardia, dyspnea, fatigue after mild activity
Anxiety	Chronic	Nervous exhaustion, restlessness, insomnia, tremors, muscle tension
Cancer	Insidious	Unexplained fatigue, pain, weight loss, anorexia, abnormal bleeding, palpable mass
Chronic fatigue syndrome	Chronic, debilitating	Severe fatigue, sore throat, myalgia, cognitive dysfunction
COPD	Progressive	Fatigue, dyspnea, chronic productive cough, weight loss, barrel chest, poor exercise tolerance
Depression	Persistent, unrelated to exertion	Fatigue, insomnia or hypersomnia, anorexia, headaches, slowed speech, feelings of worthlessness
Diabetes mellitus	Insidious or abrupt	Fatigue, polyuria, polydipsia, polyphagia, blurred vision, weight changes
Heart failure	Chronic	Fatigue, exertional dyspnea, orthopnea, edema, palpitations, crackles, S3 gallop
Hypercortisolism	Gradual	Fatigue, sleep disturbance, truncal obesity, moon face, buffalo hump, hypertension, muscle weakness
Hypothyroidism	Gradual	Fatigue, weight gain, cold intolerance, constipation, forgetfulness
Infection (acute or chronic)	Acute/chronic	Fever, malaise, site-specific symptoms (e.g., cough, dysuria), low-grade fever in chronic infections
Lyme disease	Gradual	Fatigue, malaise, headache, fever, expanding erythema migrans, arthralgia, cardiac or neurologic complications
Malnutrition	Chronic	Easy fatigability, lethargy, weight loss, muscle wasting, pallor, edema, dry flaky skin
Metabolic syndrome	Chronic	Fatigue, sluggishness, central obesity, dysglycemia, hypertension, abnormal lipid profile
Myasthenia gravis	Progressive, exertion-related	Fatigable muscle weakness, worsens throughout the day, improves with rest
Renal failure	Acute or chronic	Fatigue, lethargy, nausea, vomiting, ammonia breath, oliguria, electrolyte imbalance, neurological changes
Systemic lupus erythematosus	Chronic	Fatigue, malaise, low-grade fever, joint pain, butterfly rash, photosensitivity
Valvular heart disease	Progressive	Fatigue, exertional dyspnea, cough, cardiac murmur

Other Causes:

Carbon monoxide poisoning: headache, confusion, dyspnea
Drugs: antihypertensives, sedatives, antihistamines, cardiac glycosides
Surgery: temporary fatigue due to anesthesia, sleep deprivation, and metabolic stress

Special Considerations

Pace activities and plan rest periods for patients with organic causes
Address pain, nausea, or malnutrition to reduce chronic fatigue
Refer to psychological counseling for psychogenic fatigue
Consider age-specific factors: growth phases in children, insidious fatigue in older adults

Patient Education & Counseling

Advise on lifestyle modifications, including diet, exercise, and rest
Stress importance of pacing activities and planning sleep
Teach stress management techniques

Pediatric Considerations

Fatigue may indicate accelerated growth, psychological stress, or drug use
Assess activity levels and school performance

Geriatric Considerations

Insidious fatigue may mask serious conditions, e.g., temporal arteritis, cardiac, or endocrine disorders

References

Froyd C, Millet GY, Noakes TD. The development of peripheral fatigue and short-term recovery during self-paced high-intensity exercise. J Physiol. 2012;591:1339–46.
Goodall S, Gonzalez-Alonso J, Ali L, Ross EZ, Romer LM. Supraspinal fatigue after normoxic and hypoxic exercise in humans. J Physiol. 2012;590:2767–78.