Definition
Chronic cough, when there is an irritant in the lungs, trachea, larynx, pharynx, nasal passages, or nose, the normal reaction of our body is to cough. It’s a result of our airway nerves sending a message to our brain. But once the airway has been cleared, the coughing should stop. Your child should be checked out by a doctor if, for four weeks or more, a daily cough persists. At this point, it is considered chronic.
Before looking at serious problems, physicians usually try to rule out the most common causes first. If, after traditional treatments, the cough persists, it’s time to look into more complicated reasons. In some cases, a specialist may be recommended.
Types of Chronic cough
There are several different types of chronic (or persistent) cough. Examples include:
Dry cough: is a persistent dry cough is a cough that does not produce any mucus, is irritating to the lungs and throat, and maybe a sign of a viral infection or sinus problems
Chronic wet cough: is a cough that produces mucus (sputum), and depending on the color, may indicate a bacterial infection or fluid in the lungs (congestive heart failure)
Stress cough: a reflexive spasm of the airways caused when you are under stress. It usually produces no mucus and is not generally related to infections.
‘Barking’ cough’: is usually found in children, and may be associated with croup or other viral illness. The harsh, barking sound of a croup cough is caused by a swollen windpipe (trachea).
Whooping cough: is a cough that causes a ‘whooping’ sound after the cough may be indicative of a serious infection and should be evaluated by a doctor. Whooping cough (pertussis) is a highly contagious respiratory disease that can be deadly for babies under 1 year of age.
Risk factors
Take note of the following risk factors for chronic cough:
Smoking: The foreign substances in tobacco smoke can lead to a “smoker’s cough” – a result of the airways constantly trying to clear itself of chemicals. Heavy smokers often develop chronic bronchitis after 40 years of age.
Asthma and/or allergies: Allergies can lead to swelling of the airways, post-nasal drip and resultant coughing. Poorly controlled asthma is another risk factor for chronic cough. In some people, asthma presents mostly as a cough (without the characteristic labored breathing).
Irritants in the home or work environment: Exposure to dust, pollen, pet dander, chemicals, industrial pollution and other irritants can all increase the risk for chronic cough.
Chronic lung disease: Conditions such as emphysema and chronic bronchitis cause persistent irritation and inflammation in the airways, leading to chronic cough.
Gender: Women have a more sensitive cough reflex, increasing their risk for developing a chronic cough.
Obesity: A link between obesity and chronic respiratory diseases is increasingly being recognised. Obesity can also increase one’s risk for gastro-oesophageal reflux disease (GORD), which could lead to chronic coughing.
Causes of Chronic cough
Some of the more common causes of chronic cough include:
Common causes
Asthma: Asthma occurs when a person’s upper airways are especially sensitive to cold air, irritants in the air, or exercise. One type of asthma, known as cough-variant asthma, specifically causes a cough.
Bronchitis: Chronic bronchitis causes long-term inflammation of the airways that can cause a cough. This can be a part of an airway disease called chronic obstructive pulmonary disease (COPD) that typically occurs as a side effect of smoking.
Gastroesophageal reflux disease (GERD): GERD occurs when acid comes back up from a person’s stomach and into their throat. The result can be chronic irritation in the throat that leads to a cough.
Lingering after-effects of infection: If a person has had a severe infection, such as pneumonia or the flu, they might still experience lingering effects that include a chronic cough. Even though most of their symptoms have gone away, the airways may still remain inflamed for some time.
Postnasal drip: Also known as upper airway cough syndrome, a postnasal drip is the result of mucus dripping down the back of the throat. This irritates the throat and triggers a cough reflex.
Blood pressure-lowering medications: Medications known as angiotensin-converting enzyme (ACE) inhibitors can cause a chronic cough in some people. These medications end in -pril and include benazepril, captopril, and ramipril.
Less-common causes
Some less common causes of a chronic cough include:
Aspiration: Aspiration is the medical term for when food or saliva goes down the airway instead of the food pipe. The excess fluid can collect bacteria or viruses and may lead to irritation of the airway. Sometimes aspiration can lead to pneumonia.
Bronchiectasis: Excess mucus production can cause the airways to become larger than normal.
Bronchiolitis: Bronchiolitis is a common condition that affects children. It is caused by a virus that causes inflammation of the bronchioles, which are small airways in the lungs.
Cystic fibrosis: Cystic fibrosis causes excess mucus in the lungs and airways, which can cause a chronic cough.
Heart disease: Sometimes coughing and shortness of breath can be symptoms of heart disease or heart failure. This is called a heart cough. A person with this condition may notice their cough worsens when they are lying completely flat.
Lung cancer: While rare, persistent coughing can be a sign of lung cancer. A person with this disease may also experience chest pain as well as blood in their sputum.
Sarcoidosis: This is an inflammatory disorder that causes small growths to develop in the lungs, lymph nodes, eyes, and skin.
Mechanism of cough
Chronic cough symptoms
A chronic cough may be accompanied by other cold symptoms, including:
- Sore throat
- Postnasal drip
- Runny or stuffy nose
- Hoarseness
- Heartburn
- A bad taste in the mouth
- Phlegm
See a doctor immediately if you have a chronic cough and experience the following serious symptoms:
- Wheezing or difficulty breathing
- Fever
- Chest pain
- Coughing up blood or yellow or green phlegm
- Coughing so hard it makes you vomit
- You have a cough with unexplained weight loss
Complications
Having a persistent cough can be exhausting. Coughing can cause a variety of problems, including:
- Sleep disruption
- Headache
- Dizziness
- Vomiting
- Excessive sweating
- Loss of bladder control (urinary incontinence)
- Fractured ribs
- Passing out (syncope)
Diagnosis and test
Your doctor will ask about your medical history and perform a physical exam. A thorough medical history and physical exam can provide important clues about a chronic cough. Your doctor may also order tests to look for the cause of your chronic cough.
However, many doctors opt to start treatment for one of the common causes of chronic cough rather than ordering expensive tests. If the treatment doesn’t work, however, you may undergo testing for less common causes.
Imaging tests
X-rays: Although a routine chest X-ray won’t reveal the most common reasons for a cough postnasal drip, acid reflux or asthma it may be used to check for lung cancer, pneumonia and other lung diseases. 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 chronic cough or your sinus cavities for pockets of infection.
Lung function tests
These simple, non-invasive tests, such as spirometry, are used to diagnose asthma and COPD. They measure how much air your lungs can hold and how fast you can exhale.
Your doctor may request an asthma challenge test, which checks how well you can breathe before and after inhaling the drug methacholine (Provocholine).
Lab tests
If the mucus that you cough up is coloured, your doctor may want to test a sample of it for bacteria.
Scope tests
If your doctor isn’t able to find an explanation for your cough, special scope tests may be considered to look for possible causes. These tests may include:
Bronchoscopy: Using a thin, flexible tube equipped with a light and camera (bronchoscope), your doctor can look at your lungs and air passages. A biopsy can also be taken from the inside lining of your airway (mucosa) to look for abnormalities.
Rhinoscopy: Using a fiberoptic scope (rhinoscope), your doctor can view your nasal passageways, sinuses and upper airway.
Treatment
Treatment depends on the cause of your chronic cough.
Smoking: Stop smoking. See your doctor for suggestions if you have difficulty stopping.
Allergies: If you have a postnasal drip from allergies, avoid the things that bother your nose and throat. That might be dust, smoke, the outdoors, pets, cleaning products and deodorizers, and chemical fumes. Some over-the-counter medicines can help your allergy symptoms. If that doesn’t help, ask your doctor for prescription medicine.
Acid reflux (heartburn): If you have acid reflux, try raising the head of your bed about 4 inches. Avoid overeating and consuming things that trigger your cough. Don’t eat or drink for a few hours before you lie down. Ask your doctor about over-the-counter or prescription medicines that can help relieve the acid in your stomach. This reduces acid reflux.
Asthma: If you have asthma, your doctor will help you decide on the right treatment for your symptoms.
Medicine: If you are taking a medicine that causes you to cough, your doctor might be able to prescribe another medicine for you. Don’t stop taking the medicine unless your doctor gives you permission.
Medications used to treat chronic cough may include
Antihistamines, corticosteroids, and decongestants: These drugs are the standard treatment for allergies and postnasal drip.
Inhaled asthma drugs: The most effective treatments for asthma-related cough are corticosteroids and bronchodilators, which reduce inflammation and open up your airways.
Antibiotics: If a bacterial, fungal or mycobacterial infection is causing your chronic cough, your doctor may prescribe medications to address the infection.
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.
Prevention of Chronic cough
To prevent chronic cough:
- Quit smoking, or don’t start smoking, since this is the most common reason for chronic cough.
- Avoid contact with anyone you know who may have bronchitis or pneumonia.
- Eat fruit and foods that contain fiber. Research suggests that a combination of fiber and flavonoids found in fruit may prevent chronic cough.
To relieve the symptoms of chronic cough:
- Drink plenty of water (at least eight 8-ounce glasses a day).
- Gargle with warm salt water to help remove any mucus.
- Inhale steam.
- Avoid inhaling dust, smoke or other pollutants as much as possible.
- Use extra pillows at night to prop up your head and upper body.
- Try cough lozenges.
- Try over-the-counter cough medicines that contain guaifenesin and/or dextromethorphan.