Differential Diagnosis for Fatigue

• Single Most Likely Diagnosis
  • Anemia: This is often considered due to its high prevalence and the fact that fatigue is a common presenting symptom. Anemia can result from various causes, including iron deficiency, vitamin B12 deficiency, or chronic diseases.
• Other Likely Diagnoses
  • Hypothyroidism: A condition where the thyroid gland doesn't produce enough thyroid hormones, leading to fatigue among other symptoms.
  • Diabetes Mellitus: Both type 1 and type 2 diabetes can cause fatigue due to high blood sugar levels, which can lead to feelings of tiredness.
  • Chronic Fatigue Syndrome (CFS): Also known as Myalgic Encephalomyelitis (ME), this condition is characterized by extreme fatigue that cannot be explained by any underlying medical condition.
  • Depression: A mental health disorder that can cause persistent feelings of sadness, hopelessness, and fatigue.
• Do Not Miss Diagnoses
  • Addison's Disease: A rare disorder of the adrenal glands where not enough cortisol and aldosterone are produced, leading to fatigue among other severe symptoms.
  • Sleep Apnea: A serious sleep disorder where breathing stops and starts during sleep, leading to poor sleep quality and daytime fatigue.
  • Heart Failure: A condition where the heart cannot pump enough blood to meet the body's needs, leading to fatigue, among other symptoms.
  • Chronic Obstructive Pulmonary Disease (COPD): A group of lung diseases that block airflow and make it difficult to breathe, leading to fatigue.
• Rare Diagnoses
  • Porphyria: A group of disorders that can cause fatigue, among other symptoms, due to a buildup of natural chemicals that produce porphyrin in the body.
  • Mitochondrial Myopathies: A group of disorders that affect the mitochondria, leading to fatigue and muscle weakness.
  • Amyloidosis: A condition caused by an abnormal protein called amyloid that can accumulate in various organs, leading to fatigue among other symptoms.
  • Multiple Sclerosis: A chronic and often disabling autoimmune disease that affects the central nervous system, causing fatigue, among other symptoms.