Differential Diagnosis for Unexplained Weight Loss
Single Most Likely Diagnosis
- Depression: Unexplained weight loss is a common symptom of depression, which can lead to changes in appetite and eating habits, resulting in weight loss.
Other Likely Diagnoses
- Diabetes Mellitus: Uncontrolled diabetes can cause weight loss due to the body's inability to use glucose for energy, leading to the breakdown of fat and muscle for fuel.
- Hyperthyroidism: An overactive thyroid gland can increase metabolism, leading to weight loss despite increased appetite.
- Chronic Obstructive Pulmonary Disease (COPD): COPD can cause weight loss due to the increased energy expenditure associated with breathing and the systemic effects of chronic inflammation.
- Gastrointestinal Disorders (e.g., Celiac Disease, Crohn's Disease): Malabsorption of nutrients can lead to weight loss, as the body is unable to utilize the nutrients from food.
Do Not Miss Diagnoses
- Cancer (e.g., Pancreatic, Lung, Stomach): Unexplained weight loss is a common presenting symptom of various types of cancer, and early detection is crucial for treatment and prognosis.
- AIDS: Weight loss is a common symptom of advanced HIV infection, and timely diagnosis and treatment are essential to prevent progression to AIDS.
- Tuberculosis: Weight loss is a common symptom of TB, particularly in its advanced stages, and prompt diagnosis and treatment are critical to prevent complications and transmission.
Rare Diagnoses
- Addison's Disease: A rare endocrine disorder characterized by the inadequate production of cortisol and aldosterone, which can cause weight loss, among other symptoms.
- Pheochromocytoma: A rare tumor of the adrenal gland that can cause weight loss, hypertension, and other symptoms due to excessive catecholamine production.
- Whipple's Disease: A rare bacterial infection that can cause malabsorption, weight loss, and other systemic symptoms.