Differential Diagnosis

The patient presents with a six-month history of increased fatigue, which has been a recurring issue since her forties. The following differential diagnoses are considered:

• Single most likely diagnosis
  • Hypothyroidism: This condition is a common cause of fatigue, especially in middle-aged women. The patient's symptoms of fatigue, weight loss, and decreased productivity are consistent with hypothyroidism. The fact that she has experienced similar episodes of fatigue in the past, which resolved over time, could suggest a fluctuating thyroid function.
• Other Likely diagnoses
  • Anemia: A common cause of fatigue, especially in women of childbearing age or post-menopausal women. The patient's weight loss and fatigue could be indicative of anemia, although there are no other specific symptoms mentioned.
  • Depression: Fatigue is a common symptom of depression, and the patient's decreased productivity and weight loss could be indicative of a depressive disorder.
  • Chronic Fatigue Syndrome: Given the patient's recurring episodes of fatigue, chronic fatigue syndrome is a possible diagnosis. However, the lack of other symptoms such as muscle pain, joint pain, or headaches makes this diagnosis less likely.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Sleep Disorder (e.g., Insomnia, Restless Leg Syndrome): Although the patient reports sleeping 7 hours per night, a sleep disorder could still be contributing to her fatigue. It is essential to rule out any underlying sleep disorders.
  • Adrenal Insufficiency: This rare condition can cause fatigue, weight loss, and decreased productivity. Although it is unlikely, it is crucial to consider adrenal insufficiency as a potential diagnosis due to its severity.
  • Cancer (e.g., Lymphoma, Leukemia): Unintentional weight loss and fatigue can be symptoms of underlying cancer. Although the patient does not have other symptoms such as night sweats or fevers, it is essential to consider cancer as a potential diagnosis.
• Rare diagnoses
  • Mitochondrial Myopathies: These rare genetic disorders can cause fatigue, muscle weakness, and other symptoms. Although unlikely, they should be considered in the differential diagnosis.
  • Pernicious Anemia: A rare cause of anemia due to vitamin B12 deficiency, which can cause fatigue, weight loss, and other symptoms.
  • Addison's Disease: A rare endocrine disorder that can cause fatigue, weight loss, and decreased productivity. Although unlikely, it is essential to consider Addison's disease as a potential diagnosis due to its severity.