Key Points

• A cough is a natural reflex that protects your lungs. Coughing helps clear your airways of lung irritants, such as smoke and mucus (a slimy substance). This helps prevent infection. A cough also can be a symptom of a medical problem.
• Prolonged coughing can cause unpleasant side effects, such as chest pain, exhaustion, light-headedness, and loss of bladder control. Coughing also can interfere with sleep, socializing, and work.
• Coughing occurs when the nerve endings in your airways become irritated. Certain irritants and allergens, medical conditions, and medicines can irritate these nerve endings.
• A cough can be acute, subacute, or chronic, depending on how long it lasts. An acute cough lasts less than 3 weeks. A subacute cough lasts 3 to 8 weeks. A chronic cough lasts more than 8 weeks.
• When you cough, mucus (a slimy substance) may come up. Coughing helps clear the mucus in your airways from a cold, bronchitis, or other condition. Rarely, people cough up blood. If this happens, you should call your doctor right away.
• If your cough is a symptom of a medical condition, it may occur with other signs and symptoms of that condition. For example, if you have a cold, you may have a runny or stuffy nose. If you have gastroesophageal reflux disease, you may have a sour taste in your mouth.
• Your doctor will diagnose the cause of your cough using your medical history, a physical exam, and the results from tests.
• The best way to treat a cough is to treat its cause. However, sometimes the cause is unknown. Cough medicines usually are used only when the cause of the cough is unknown and the cough causes a lot of discomfort.
• No evidence shows that cough and cold medicines relieve a cough in children. These medicines can even harm children. Talk to your child's doctor about your child's cough and how to treat it.
• Follow the treatment plan your doctor gives you for treating the cause of your cough. Ask your doctor about ways to relieve your cough. Try to follow a healthy lifestyle. For example, if you smoke, quit. Try to avoid irritants and allergens that make you cough. Follow a healthy diet and be as physically active as you can.