Differential Diagnosis for Fatigue
The differential diagnosis for fatigue is extensive and can be categorized into several groups. Here's a breakdown of the possible causes:
Single Most Likely Diagnosis
- Depression: Fatigue is a common symptom of depression, and it's essential to consider this diagnosis, especially if the patient has a history of mental health issues or is experiencing other depressive symptoms.
- Anemia: Iron-deficiency anemia is a common cause of fatigue, particularly in women of childbearing age. A simple blood test can help diagnose this condition.
- Hypothyroidism: An underactive thyroid gland can cause fatigue, weight gain, and other symptoms. This diagnosis is more likely in patients with a family history of thyroid disease or those taking certain medications.
Other Likely Diagnoses
- Sleep Apnea: This condition, characterized by pauses in breathing during sleep, can lead to fatigue, daytime sleepiness, and other symptoms.
- Diabetes: Uncontrolled diabetes can cause fatigue, thirst, and frequent urination.
- Chronic Fatigue Syndrome: A condition characterized by persistent fatigue that is not relieved by rest and is often accompanied by other symptoms like muscle pain and sleep disturbances.
- Medication Side Effects: Certain medications, such as sedatives, antidepressants, and antihistamines, can cause fatigue as a side effect.
- Dehydration: Inadequate fluid intake or excessive fluid loss can lead to fatigue, headaches, and other symptoms.
Do Not Miss Diagnoses
- Addison's Disease: A rare condition where the adrenal glands do not produce enough cortisol and aldosterone, leading to fatigue, weight loss, and other symptoms.
- HIV/AIDS: Fatigue can be an early symptom of HIV infection, and it's essential to consider this diagnosis, especially in high-risk patients.
- Cancer: Certain types of cancer, such as leukemia or lymphoma, can cause fatigue, weight loss, and other symptoms.
- Heart Failure: Fatigue, shortness of breath, and swelling in the legs can be symptoms of heart failure, a condition where the heart is not pumping enough blood to meet the body's needs.
Rare Diagnoses
- Mitochondrial Myopathies: A group of rare genetic disorders that affect the mitochondria, leading to fatigue, muscle weakness, and other symptoms.
- Porphyria: A group of rare genetic disorders that can cause fatigue, abdominal pain, and other symptoms.
- Wilson's Disease: A rare genetic disorder that causes copper accumulation in the body, leading to fatigue, liver disease, and other symptoms.
- Myasthenia Gravis: A rare autoimmune disorder that causes muscle weakness, fatigue, and other symptoms.