What is a chronic cough
An occasional cough helps to protect your lungs by getting rid of unwanted material and this is normal. However, a chronic cough is one that persists for a more than 8 weeks. It may be productive of sputum or blood, cause a disturbance in your sleep, or affect school or work and it should prompt a referral to your GP or a lung specialist.
Causes of a chronic cough
There are a number of causes of chronic cough. Some of the more common causes include:
- Postnasal drip. When your nose or sinuses produce extra mucus, it can drip down the back of your throat and trigger your cough reflex.
- Asthma. An asthma-related cough can be variable and change with the seasons, appear after an infection of the upper respiratory tract, or become worse when you’re exposed to cold air, certain chemicals or fragrances.
- Gastroesophageal reflux disease (GERD). Reflux occurs when stomach acid flows back into your food pipe (esophagus). The constant irritation can lead to chronic coughing, which in turn can worsen the relux, making this a vicious cycle.
- Infections. A lingering cough post a viral or bacterial infection can occur.
- Blood pressure drugs. Angiotensin-converting enzyme (ACE) inhibitors, commonly prescribed for high blood pressure and heart failure, can cause chronic cough in some people.
- Chronic bronchitis. This is an inflammation of your major airways (bronchial tubes) can cause a cough that brings up sputum. Most people with chronic bronchitis are current or former smokers and may have other smoking related lung problems.
- Laryngeal hypersensitivity. This can occur when the back of your throat becomes sensitive to things like cold air, talking, funny odours, or certain chemicals.
Risk factors for a chronic cough
Being a current or former smoker, or being exposed to second hand smoke, is one of the leading risk factors for chronic cough. Women tend to have more-sensitive cough reflexes, so they’re more likely to develop a chronic cough than are men.
When to see a doctor
See your doctor if you have a cough that lingers for weeks, especially one that brings up sputum or blood, disturbs your sleep, or affects school or work. We offer a chronic cough service where a systematic approach to investigate and manage you.
Our chronic cough service:
A lung specialist will undertake a thorough history and examination and undertake further testing if necessary. Some investigations that may be conducted include:
- X-rays: A chest Xray may be useful in looking for some causes of chronic cough such as infections, scarred lungs or other lung lesions. However it will not be helpful in looking for post nasal drip, asthma or reflux. An X-ray of your sinuses may reveal evidence of a sinus infection.
- Computerized tomography (CT) scans: CT scans also may be used to check your lungs for conditions that may produce cough or your sinus cavities for pockets of infection. It is a more sensitive test that provides more in depth images of your lungs.
- Lung function tests: These simple, noninvasive tests are used to diagnose asthma and COPD. They measure how much air your lungs can hold and how fast you can exhale.
- Sputum Tests: If you are producing sputum, this can be sent off to the lab to be tested for bacteria, fungi or other cells.
- Scope tests: If the reason for your cough remains evasive then special scope tests may be considered to look for possible causes. These tests use a thin, flexible tube equipped with a light and camera that can be used to look into your lungs. A biopsy can also be taken from the inside lining of your airway (mucosa) to look for abnormalities.
Treatment of Chronic cough
Management of chronic cough is aimed at treating the underlying problem and will be individualized. Treatment options include:
- Antihistamines, glucocorticoids and decongestants. These drugs are standard treatment for allergies and postnasal drip.
- Inhaled asthma drugs. The most effective treatments for asthma-related cough are glucocorticoids and bronchodilators, which reduce inflammation and open up your airways.
- Antibiotics. If a bacterial infection is causing your chronic cough, your doctor may prescribe antibiotics.
- Acid blockers. When lifestyle changes don’t take care of acid reflux, you may be treated with medications that block acid production. Some people need surgery to resolve the problem.
- Cough suppressants. If the reason for your cough can’t be determined and it’s causing serious problems for you, such as keeping you from sleeping, your doctor may prescribe a cough suppressant. However, there’s no evidence that over-the-counter cough medicines are effective.
- Other newer agents: There are newer agents that have been trialed in smaller studies and can be used if other treatments are not appropriate or have not worked so don’t worry, there are a number of options.