There are usually no obvious signs before the onset of tuberculosis, but systemic symptoms such as fever and respiratory symptoms will appear in the early stage of the disease. 1. Systemic symptoms: the most common clinical symptom caused by the onset of tuberculosis is fever, and the fever caused by the disease is usually a prolonged low-grade fever, which starts in the late afternoon or evening every day and returns to normal in the morning of the next day, and may be accompanied by symptoms such as fatigue, night sweats, and tiredness, etc. The disease belongs to the respiratory system. 2. Respiratory symptoms: TB belongs to the respiratory system, so the disease will bring respiratory symptoms, commonly coughing up sputum, chest pain, hemoptysis, etc. Every patient with TB will show symptoms such as coughing up sputum, chest pain, hemoptysis, and so on. There are some differences in the symptoms shown by each TB patient, but if you have unexplained cough and low-grade fever for a long time, you should pay attention to consult a doctor in time.