Tuberculosis is a highly contagious respiratory disease caused by the infection of Mycobacterium tuberculosis in the lungs, generally transmitted through respiratory droplets or direct contact.

When infected with tuberculosis, symptoms that often appear include low-grade fever in the afternoons, coughing, expectoration, hemoptysis, chest pain, chest tightness, and shortness of breath. Some may experience weight loss, fatigue, and night sweats. Therefore, when patients with pulmonary tuberculosis exhibit an afternoon low-grade fever, it often leads to the occurrence of headaches.

Therefore, it is very common for patients in the early stages of pulmonary tuberculosis to exhibit various symptoms, primarily due to the rise in body temperature.