Differential Diagnosis for Weight Loss
- Single Most Likely Diagnosis
- Malignancy (e.g., cancer): This is often considered the single most likely diagnosis for unintentional weight loss, especially in older adults, due to the high prevalence of cancer and its potential to cause significant weight loss.
- Other Likely Diagnoses
- Diabetes Mellitus: Uncontrolled diabetes can lead to weight loss due to the body's inability to properly use glucose, leading to the breakdown of fat for energy.
- Hyperthyroidism: An overactive thyroid gland can increase metabolism, leading to weight loss despite increased appetite.
- Gastrointestinal Disorders (e.g., celiac disease, Crohn's disease, ulcerative colitis): These conditions can lead to malabsorption of nutrients, resulting in weight loss.
- Chronic Infections (e.g., tuberculosis, HIV/AIDS): Chronic infections can cause weight loss due to increased metabolic demands and decreased appetite.
- Do Not Miss Diagnoses
- Cancer: Although listed as the single most likely diagnosis, it's crucial to reiterate the importance of not missing a diagnosis of cancer, as early detection significantly improves prognosis.
- Pheochromocytoma: A rare tumor of the adrenal gland that can cause weight loss, among other symptoms like hypertension and palpitations.
- Addison's Disease: A rare disorder of the adrenal glands that can cause weight loss, fatigue, and changes in skin pigmentation.
- Rare Diagnoses
- Whipple's Disease: A rare, systemic bacterial infection that can cause weight loss, diarrhea, and abdominal pain.
- Lymphoma: A type of cancer that affects the immune system and can cause weight loss, among other symptoms.
- Amyloidosis: A condition characterized by the deposition of abnormal proteins (amyloid) in various tissues, which can lead to weight loss and other systemic symptoms.