A little pain in the left chest with deep inhalation is not necessarily tuberculosis. In addition to tuberculosis, there are other diseases such as lung cancer, pleurisy, costochondritis and pneumonia. 1. Tuberculosis: If there is a little pain in the left chest with deep inhalation, if it is accompanied by coughing and sputum for more than 2 weeks, or (and) accompanied by low-grade fever, night sweats and other symptoms, and there is a history of contact with tuberculosis patients, it should be taken seriously. 2. Lung cancer: when lung cancer involves the pleura, chest pain can also be manifested, accompanied by unexplained emaciation, cough, sputum and other symptoms. 3. Pleurisy: pleurisy is generally characterized by chest pain due to various reasons, which is mostly caused by fibrous exudation, increased friction of pleura of dirty layer and wall layer, and pleurisy can be accompanied by pleural effusion if it is serious. 4. costochondritis: the cause of costochondritis may be viral infection, chronic strain of thoracic and rib joint ligaments, endocrine abnormalities and other factors. Patients may have left anterior chest pain and pressure pain, which can be induced or aggravated by deep breathing. 5. Pneumonia: inflammation of terminal airways, alveoli and interstitial lungs, in addition to cough, sputum, fever, shortness of breath, some patients have chest pain manifestations, generally associated with respiratory muscle strain and pleural invasion. If the left chest hurts a little bit when you inhale deeply, you should go to the local hospital to complete the relevant examinations, such as chest CT, sputum smear, sputum culture, etc., so as to make a clear diagnosis and standardize the treatment as soon as possible.