Coughing is a natural reflex action that serves to promote proper breathing and prevent infection by clearing the throat of irritants.

An occasional cough, whether intentional or involuntary, is normal and beneficial. The acute coughing that accompanies colds, flu and other upper respiratory infections usually subsides within a week or two without any lasting effect.

But a chronic cough—one that persists longer than 8 weeks in an adult or 4 weeks in a child—is nothing to sneeze at. In addition to being annoying, a chronic cough can be harmful, and more often than not is an indication of an underlying problem.

Chronic Cough Causes

In most people, a cough is usually associated with an infection like the common cold. In these instances, the cough starts out as one of the body's protective responses against the virus. However, side effects of the illness, like postnasal drip, can prompt further coughing.

The 3 most common causes of chronic cough are asthma, a chronic lung condition that inflames and narrows the airways; postnasal drip, when excess mucus from the nose or sinus drips down the back of the throat; and gastro-esophageal reflux, when stomach acid backs up into the throat.

Other potential sources of persistent coughing include:

  • Allergies
  • Chronic obstructive pulmonary disease (COPD)
  • Heart ailments
  • Smoking
  • Bronchitis
  • Pneumonia
  • Tuberculosis

Rarely, cancer can be a cause.

Chronic Cough Diagnosis

Chronic cough is not a disease; it’s a symptom. In order to make it stop you have to find the cause.

Seeing a doctor for evaluation and treatment is important because a chronic cough can disturb sleep, interfere with work and contribute to a variety of physical ills, including fatigue, dizziness, headaches, chest pain, urinary incontinence, excessive sweating, fractured ribs and even blackouts.

Your physician will take a methodical approach in investigating the cause of a chronic cough. The evaluation will include a physical examination and a review of your medical history, family history and personal habits, plus environmental factors.

In the majority of cases, this process enables doctors to pinpoint the reason behind the nagging cough. But, depending on your circumstances and symptoms, the evaluation also may entail one or more diagnostic procedures, including:

  • Imaging of the chest, sinus or esophagus
  • Allergy testing
  • Lung function testing
  • Analysis of blood, mucus or phlegm
  • Immune system assessment
  • Speech and vocal cord evaluation

Chronic Cough Treatment

Treating a chronic cough may involve specialists from one or more of many areas of medicine including allergy and immunology, ENT, pulmonology, gastroenterology, cardiology. A primary care physician is your best resource to begin an evaluation and to coordinate a multidisciplinary treatment plan.

There are effective therapies for virtually all of the underlying causes of a chronic cough. These include inhalers for asthma, antihistamines and decongestants for postnasal drip, acid blockers for acid reflux, antibiotics for infections and medications for high blood pressure that don’t trigger coughing. Some common causes of chronic cough also can be addressed by lifestyle changes – quitting smoking, avoiding allergens and irritants, eating a healthier diet.

In the relatively rare case in which the cause for a cough cannot be identified, doctors usually prescribe cough suppressants. These medicines won’t “cure” a persistent cough, but they can provide a degree of relief.