Fatigue

Question 0

Fatigue: general

Answer 0

• ## differentiate fatigue from muscle weakness; not directly related to exertion, but refers to lack of NRG or sense of being tired

Question 1

Laboratory studies in workup of fatigue

Answer 1

1. CBC (anemia)
2. TSH (hypothyroidism)
3. Fasting glucose (diabetes mellitus)
4. BMP (electrolyte abnormalities)
5. Urinalysis, BUN/Creatinine (renal disease)
6. LFT (liver disease)

Question 2

Ddx fatigue

Answer 2

• psychiatric cause: depression (most common); anxiety, somatization
• endocrine: hypothyroidism, poorly controlled DM, apathetic hyperthyroidism of elderly pts, Addison’s disease, hypopituitarism, hyperparathyroidism, other causes of hypercalcemia
• hematologic/oncologic causes: severe anemia, occult malignancy (eg pancreatic carcinoma)
• metabolic causes: chronic renal failure ,hepatocellular failure
• infectious dzs: mononucleosis, viral hepatitis, HIV, syphilis, hep B and C, CMV parasitic dz, tuberculosis, subacute bacterial endocarditis, LYme dz
• cardiopulmonary dz: obstructive sleep apnea, CHF
• meds: antihypertensive meds (clonidine, methyldopa), antidepressants (amitryptyline, doxepin, trazodone are more sedating), hypnotics, beta blockers, antihistamines, drug abuse/withdrawal
• other: chronic fatigue syndrome, fibromyalgia, sleep disturbances (sleep apnea, narcolepsy, insomnia)

Question 3

Etiology of chronic fatigue

Answer 3

• only 5% of cases are diagnosed as chronic fatigue syndrome
• most cases of chronic fatigue: due to depression, anxiety, or both (up to 2/3)
• bw 20-25% of cases are idiopathic, but do not fit criteria for chronic fatigue syndrome
• <5% due to unidentified medical illness

dx of exlcusion

more commom in women