Many conditions cause symptoms similar to acute bronchitis. Some of those conditions include:

• Pneumonia, a potentially serious infection of the lungs. Pneumonia can make it hard to breathe.
• Asthma, a long-term (chronic) disease of the airways of the lungs. Symptoms include periodic episodes of difficulty breathing, wheezing, chest tightness, and coughing.
• Allergies, which are an overreaction of the immune system to usually harmless substances. Symptoms include cough and difficulty breathing. Allergic rhinitis (hay fever) is a common allergy.
• Exposure to chemicals at work (occupational exposure).
• Cold, influenza, or other upper respiratory infections.
• Sinusitis, an infection of the mucous membranes that line the inside of the nose and facial sinuses. Symptoms include pain and a chronic cough that produces mucus.
• Mild heart failure. In heart failure, your heart is not able to pump blood effectively. Shortness of breath is one of the symptoms.
• Bronchiolitis (in young children), an inflammation of the small air passages (bronchioles) in the lungs. Symptoms include difficulty breathing and cough.
• Gastroesophageal reflux disease (GERD), the abnormal backflow of stomach acid into the esophagus. This can cause cough and chest discomfort.
• Lung cancer. Symptoms include cough and shortness of breath.