Final answer:
Bronchitis is an inflammation of the bronchi, characterized by a cough that produces phlegm or mucus. It is usually caused by viruses or bacteria and can be treated with antibiotics.
Step-by-step explanation:
Bronchitis is an inflammation of the bronchi, the air passages that conduct air into the lungs. It is usually caused by viruses or bacteria and is characterized by a cough that produces phlegm or mucus. Symptoms include shortness of breath and wheezing. Acute bronchitis is usually treated with antibiotics.