How is pulmonary tuberculosis diagnosed?
Aug 10, 2022
Source: Cainiu Health
Dr. Guo Xiheng
Introduction
For pulmonary tuberculosis, the initial diagnostic steps include:
- Chest imaging studies (e.g., chest X-ray or CT), which clearly reveal the presence of tuberculous lesions in the lungs, as well as their size, extent, density, and morphology.
- Sputum examination, including acid-fast bacilli (AFB) smear microscopy and sputum culture for *Mycobacterium tuberculosis*.
- Bronchoscopy with bronchoalveolar lavage (BAL) and subsequent culture to detect *Mycobacterium tuberculosis*.
- Tuberculin skin test (TST), commonly known as the purified protein derivative (PPD) test.
- Laboratory diagnosis and bacteriological testing.
Once tuberculosis (TB) develops, prompt treatment is essential; otherwise, symptoms such as hemoptysis (coughing up blood) and persistent cough may worsen. Tuberculosis is a respiratory infectious disease caused by *Mycobacterium tuberculosis*. It can be treated with anti-tuberculosis medications alone or through an integrated approach combining both Western and traditional Chinese medicine. So, how is pulmonary tuberculosis diagnosed?
How Is Pulmonary Tuberculosis Diagnosed?
Initial diagnosis of pulmonary tuberculosis typically involves chest imaging studies (e.g., chest X-ray or CT scan), which clearly reveal the presence, size, extent, density, and morphology of tuberculous lesions in the lungs. Sputum examination—including sputum smear microscopy for acid-fast bacilli (AFB) and sputum culture—is also critical. Bronchoscopy with bronchoalveolar lavage (BAL) and subsequent culture may be performed to detect *M. tuberculosis*. The tuberculin skin test (TST), commonly known as the purified protein derivative (PPD) test, is another important diagnostic tool. Laboratory diagnostics—particularly bacteriological tests including sputum smear microscopy and culture—are the most specific methods for confirming pulmonary TB and serve as vital benchmarks for monitoring treatment response, identifying sources of infection, and guiding appropriate drug selection.
Using sedimentation or flotation techniques for sputum smear preparation—or employing fluorescence microscopy—can significantly improve the detection (positive) rate. In cases where spontaneous sputum production is insufficient, induced sputum collection (e.g., via early-morning tracheal washings or gastric aspirates) may be used. The tuberculin skin test remains the primary method for determining prior *M. tuberculosis* infection.
In daily life, patients should maintain regular, balanced dietary habits—avoiding spicy, irritating foods and refraining from overeating or staying up late. We hope this information proves helpful.
