Which symptom is commonly associated with active tuberculosis?

• A. Weight loss, fever, night sweats, and coughing up blood
• B. Weight gain
• C. Rash
• D. Joint pain

Answer: (A)

Active tuberculosis typically shows a combination of systemic symptoms and a persistent cough. The best-known pattern is weight loss, fever, night sweats, and coughing up blood. Weight loss and fever arise from the body's ongoing response to a long-standing infection and the metabolic strain of inflammation. Night sweats come from the inflammatory milieu and the body's attempts to fight the bacteria. Coughing up blood occurs when lung tissue and small blood vessels are damaged by the infection, which can happen with pulmonary TB, especially when cavities form in the lungs. This cluster of symptoms distinguishes active TB from many other illnesses that don’t cause this mix of systemic signs plus hemoptysis.

Other options don’t fit the common presentation. Weight gain is not typical of active TB, and rash or joint pain are not the hallmark features of pulmonary TB, though TB can affect skin or joints in less common scenarios. If someone has a persistent cough with weight loss or night sweats, it warrants evaluation for TB.