A15.0 Tuberculosis of lung

Name of the Condition

• Tuberculosis of lung (ICD-10-CM: A15.0)

Summary

Tuberculosis of the lung is a contagious bacterial infection caused by Mycobacterium tuberculosis that primarily affects the lung tissue. It spreads through airborne droplets when an individual with active TB coughs, sneezes, or speaks. This condition is a significant public health concern, particularly in areas with limited healthcare access or high poverty rates.

Causes

Tuberculosis of the lung is caused by the bacterium Mycobacterium tuberculosis. Infection occurs when a person inhales respiratory droplets containing the bacteria, typically from an individual with active TB. The bacteria can settle in the lungs and multiply, leading to infection.

Risk Factors

• Prolonged exposure to someone with active TB.
• Living in or traveling to areas with high TB prevalence.
• Compromised immune system (e.g., HIV/AIDS, diabetes).
• Substance abuse, including alcohol and tobacco.
• Malnutrition or poor living conditions.

Symptoms

• Persistent cough (lasting three weeks or more).
• Hemoptysis (coughing up blood).
• Fever, chills, and night sweats.
• Unintended weight loss.
• Chest pain or discomfort.
• Fatigue and weakness.

Diagnosis

Diagnosis involves a combination of clinical evaluation, imaging, and laboratory tests. A chest X-ray may show characteristic lung changes, while sputum tests (microscopy, culture, or nucleic acid amplification) confirm the presence of Mycobacterium tuberculosis. Additional tests, such as tuberculin skin tests or interferon-gamma release assays, may assess exposure or infection.

Treatment Options

Treatment typically involves a multi-drug regimen over several months, including isoniazid, rifampin, ethambutol, and pyrazinamide. Directly observed therapy (DOT) is often recommended to ensure adherence. Drug-resistant TB may require alternative medications and longer treatment durations.

Prognosis and Follow-Up

With appropriate treatment, most individuals with tuberculosis of the lung recover fully. However, adherence to the full course of therapy is critical to prevent relapse or drug resistance. Follow-up care includes monitoring for treatment response and potential side effects, as well as assessing for latent TB infection in close contacts.

Complications

• Pulmonary complications, such as pneumothorax or respiratory failure.
• Disseminated TB (spread to other organs).
• Drug-resistant TB, which is harder to treat.
• Long-term lung damage or scarring.

Lifestyle & Prevention

• Avoid close contact with individuals who have active TB.
• Ensure proper ventilation in living or work environments.
• Complete the full course of prescribed TB treatment.
• Maintain a healthy immune system through balanced nutrition and regular exercise.
• Seek testing if exposed to TB or experiencing symptoms.

When to Seek Professional Help

Seek medical attention if you experience a persistent cough, unexplained weight loss, fever, or other symptoms of TB. Early diagnosis and treatment are essential to prevent complications and transmission.

Tips for Medical Coders

When coding A15.0, ensure documentation specifies the lung as the site of tuberculosis. Verify that the diagnosis is confirmed by appropriate clinical or laboratory findings. Avoid using this code for latent TB or extrapulmonary TB. Document the presence of active disease, including symptoms or test results, to support code assignment.