What are lung nodules and are they serious?

Generally, pulmonary nodules may be caused by factors such as aging, long-term smoking, environmental pollution exposure, pneumonia, tuberculosis, and others. The severity of a pulmonary nodule must be determined based on its size and characteristics. Small benign nodules are usually not serious; however, large malignant nodules may be more severe. If experiencing any discomfort, timely medical consultation is recommended. Detailed explanations are as follows:

I. Causes of Pulmonary Nodules

1. Aging

With increasing age, various bodily functions gradually decline, including the lung's ability to regenerate and repair cells. Accumulated minor injuries over time may gradually form nodules. Maintaining healthy lifestyle habits such as balanced nutrition, moderate exercise, and adequate sleep is recommended.

2. Long-term Smoking

Tobacco contains numerous harmful substances such as nicotine, tar, and carbon monoxide. Prolonged smoking causes these harmful substances to continuously irritate lung tissues, potentially reducing the airway's self-cleaning capacity and allowing harmful substances to deposit in the lungs, triggering inflammatory responses and stimulating nodule formation. Quitting smoking, avoiding secondhand smoke, and consuming lung-cleansing foods such as pears and tremella are recommended.

3. Environmental Pollution Exposure

Living or working for prolonged periods in heavily polluted environments—such as areas with industrial emissions, vehicle exhaust, or high dust levels—can lead to deposition of harmful airborne substances like particulates and chemical pollutants in the alveoli and bronchi, irritating lung tissues and triggering immune responses that may lead to pulmonary nodule formation. Wearing protective masks, reducing exposure time in polluted environments, and using indoor air purifiers to improve air quality are recommended preventive measures.

4. Pneumonia

Pneumonia can be caused by various pathogens, including bacteria, viruses, and fungi. Inflammatory stimulation of lung tissue, especially when inflammation is incompletely absorbed, may lead to localized tissue proliferation and repair, forming nodules. Patients may also experience symptoms such as fever and cough. Treatment may include medications such as penicillin V potassium tablets, doxycycline hyclate tablets, and fluconazole sodium chloride injection, as directed by a physician.

5. Tuberculosis

Tuberculosis is caused by infection with Mycobacterium tuberculosis. When the body's immunity declines, this bacterium can invade and multiply in the lungs, causing inflammation and tissue necrosis. During the healing process, granulomas may form, manifesting as pulmonary nodules, and may be accompanied by symptoms such as coughing, sputum production, and low-grade fever. Treatment may include medications such as isoniazid tablets, rifampin tablets, and ethambutol hydrochloride tablets, as guided by a physician.

II. Severity of Pulmonary Nodules

Most pulmonary nodules are benign, such as those caused by inflammatory infections or benign tumors. Nodules caused by inflammation may gradually shrink or even disappear after anti-infective treatment. For example, residual nodules after pneumonia may improve once the inflammation fully resolves. Benign tumors such as hamartomas typically grow slowly and have minimal impact on lung function. As long as regular monitoring confirms no malignant transformation, they generally do not pose significant threats to patients.

However, if a pulmonary nodule is an early manifestation of malignancy, the situation is more serious. Lung cancer-related nodules may gradually enlarge over time, with morphological changes such as irregular edges, spiculated margins, and uneven internal density. Once diagnosed as a malignant nodule, prompt comprehensive treatment—including surgery, chemotherapy, radiotherapy, targeted therapy, or immunotherapy—is necessary. Even with aggressive treatment, the prognosis of lung cancer depends on multiple factors such as staging and histological type, and the survival rate remains low for patients with advanced-stage lung cancer.

Maintaining a healthy lifestyle by avoiding smoking and alcohol, avoiding harmful environments, and undergoing regular follow-up examinations of lung health is recommended.