Differential Diagnosis for Night Sweats, Weight Loss, and Lightheadedness in a 69-Year-Old Male
Single Most Likely Diagnosis
- Tuberculosis (TB): Given the combination of night sweats, weight loss, and potential for lightheadedness due to anemia or dehydration, TB is a strong consideration, especially in older adults who may have a higher risk of reactivation.
Other Likely Diagnoses
- Lymphoma: Both Hodgkin's and non-Hodgkin's lymphoma can present with systemic symptoms such as night sweats and weight loss. Lymphadenopathy might also lead to lightheadedness if it causes compression of vital structures.
- Chronic Infections (e.g., Endocarditis, Osteomyelitis): Chronic infections can cause prolonged fever, night sweats, and weight loss. Lightheadedness could result from anemia, dehydration, or embolic events in the case of endocarditis.
- Diabetes Mellitus: Uncontrolled diabetes can lead to weight loss and potentially night sweats due to nocturnal hypoglycemia. Lightheadedness could be due to hypoglycemia or dehydration from hyperglycemia.
- Hyperthyroidism: Weight loss and heat intolerance leading to night sweats are common in hyperthyroidism. Lightheadedness could result from palpitations or orthostatic hypotension.
Do Not Miss Diagnoses
- Pheochromocytoma: Although rare, this diagnosis is critical due to its potential for severe, life-threatening hypertension. Night sweats and weight loss can occur, and episodes of hypertension can cause lightheadedness.
- Hypertension or Cardiovascular Disease: Uncontrolled hypertension or heart disease can lead to symptoms of lightheadedness. While not directly causing night sweats or weight loss, these conditions are common in this age group and can have severe consequences if not addressed.
- Malignancy (e.g., Lung, Pancreatic Cancer): Various cancers can present with weight loss and night sweats. Lightheadedness could be due to anemia, dehydration, or metastatic disease affecting the brain or cardiovascular system.
Rare Diagnoses
- Brucellosis: A zoonotic infection that can cause fever, night sweats, weight loss, and potentially lightheadedness due to anemia or other systemic effects.
- Whipple's Disease: A rare bacterial infection that can cause weight loss, diarrhea, joint pains, and potentially night sweats. Lightheadedness could result from dehydration or malabsorption.
- Histiocytosis: Rare disorders like Langerhans cell histiocytosis can present with systemic symptoms including weight loss, night sweats, and potentially lightheadedness due to CNS involvement or other systemic effects.