Which of the following is NOT a symptom of tuberculosis?

Weight gain is not a symptom typically associated with tuberculosis (TB). Instead, individuals suffering from TB often experience weight loss, which can be attributed to several factors related to the disease, including decreased appetite, increased energy expenditure due to fever, and the body's response to chronic infection.

In contrast, the other options are classic symptoms of tuberculosis. A persistent cough is one of the hallmark signs, often worsening over time, and it may bring up blood or phlegm. Night sweats are also a common symptom, reflecting the body’s attempt to fight off the infection. Additionally, fever is a frequent manifestation, particularly in the evening, and is part of the systemic inflammatory response to the TB bacteria. Understanding these symptoms is crucial for early detection and treatment, emphasizing why weight gain is not aligned with the typical clinical presentation of TB.