Subtle changes in your breathing may be easy to miss, but they can be important warning signs of lung disease.

The American Lung Association says symptoms to be concerned about include:

• A cough that persists for a month or longer, or coughing up blood.
• Feeling short of breath, or having difficulty breathing.
• Persistent production of mucus that lasts for a month or longer.
• Wheezing.
• Chest pain that occurs for unknown reasons — particularly when you cough or inhale — that lasts for at least a month.

Source: HealthDay