Context: If a tuberculosis infection does become active, it most commonly involves the lungs (in about 90% of cases). Symptoms may include chest pain and a prolonged cough producing sputum. About 25% of people may not have any symptoms (i.e. they remain "asymptomatic"). Occasionally, people may cough up blood in small amounts, and in very rare cases, the infection may erode into the pulmonary artery or a Rasmussen's aneurysm, resulting in massive bleeding. Tuberculosis may become a chronic illness and cause extensive scarring in the upper lobes of the lungs. The upper lung lobes are more frequently affected by tuberculosis than the lower ones. The reason for this difference is not clear. It may be due either to better air flow, or to poor lymph drainage within the upper lungs.

Question: Which lobes of the lungs are more often affected by TB?
Answer: upper lung lobes

Question: What symptom will result if TB infection causes a Rasmussen's aneurysm?
Answer: massive bleeding

Question: What percentage of tuberculosis infections don't ever manifest in symptoms of the disease?
Answer: 25%

Question: If TB becomes chronic, what lasting effect might it have on the lung's upper lobes?
Answer: scarring

Question: Approximately what percentage of active TB cases affect the lungs?
Answer: 90%

Question: What percentage of cases include chest pain?
Answer: Unanswerable

Question: What is it called when people have symptoms?
Answer: Unanswerable

Question: What percentage of cases erode into the pulmonary artery?
Answer: Unanswerable

Question: What kind of aneurysm does chest pain in TB patients sometimes result in?
Answer: Unanswerable

Question: What are lower lobes in the lungs often more affected by?
Answer: Unanswerable