Bronchitis is an inflammation of the bronchial tubes, the airways that carry air to and from the lungs, leading to coughing and mucus production. It may be acute, often caused by viral respiratory infections and lasting several days to weeks, or chronic, a long-term condition commonly associated with smoking or prolonged exposure to lung irritants and classified as a form of chronic obstructive pulmonary disease (COPD). Symptoms typically include persistent cough, chest discomfort, wheezing, shortness of breath, fatigue, and production of clear, yellow, or green mucus. Acute bronchitis usually resolves with rest, fluids, and supportive care, while chronic bronchitis requires ongoing management to reduce inflammation, improve airflow, and prevent complications. Avoiding tobacco smoke and environmental pollutants is essential in both prevention and treatment.