Coughing is a reflex and there are various kinds. Some coughs are acute, lasting for a few weeks. Others are chronic lasting for more than two months. There are some coughs that vary in duration and can be productive or non-productive.
The origin of a cough can be elusive. Determining the cause usually leads to a diagnosis and a treatment that solves the problem.
Just because the cough is short-lived does not mean that it cannot be a significant health condition. It may be life threatening, such as when a person is suffering from congestive heart failure.
Subacute coughs can last up to eight weeks. Both subacute and chronic coughs can be indicative of other problems, or a combination of medical conditions, and be equally serious.
What makes a person cough?
A cough is a protective reflex. It is a normal physiological function that clears excessive secretions and debris from the respiratory system.
There are three components to the cough reflex.
- Afferent sensory limb (something triggers the cough).
- Central processing center (our brain interprets the need for the cough reflex).
- Efferent limb (electrical signals are sent to our muscles so we can cough).
There are many nerves involved in the cough reflex. The cough is produced through what is known as a reflex arc, which means it can incorporate a host of muscles and be repetitive.
The cough reflex also has neuroplasticity. This means that a hypersensitive response is elicited over time due to the cough itself, which causes chronic irritation and inflammation and even tissue remodeling. Hence, a chronic cough can be exaggerated and itself can contribute to the person maintaining the cough.
What if I have an acute cough?
The most common reason for an acute cough is the common cold, and usually that is not serious. However, rapid onset of a cough can mean other dangerous conditions such as:
- Pulmonary embolism.
- Congestive heart failure.
The goal is to differentiate between one of these serious conditions or an acute respiratory infection, lower respiratory infection, or a worsening of an existing condition such as:
- Bronchitis or bronchiectasis.
- Chronic obstructive pulmonary disease (COPD).
- Upper airway cough syndrome.
- Chronic sinusitis.
Treatment and resolution of the cough depends on the cause. Most acute coughs are a result of an upper respiratory infection that is viral, and it subsides when the infection is gone.
What if my cough lasts up to eight weeks or is subacute?
The first question to answer is whether the cough is a result of a lingering upper respiratory infection. If it is, or it is a result of sinusitis, it may mean that the cough and the underlying issue have not been fully addressed.
If the cough persists even after the upper respiratory infection is gone or the sinusitis is under control, then the cough needs to be addressed as being chronic.
The reasons can include the following:
- Postnasal drip.
- Upper airway irritation.
- Mucus accumulation.
- Asthma which causes bronchial hyperresponsiveness.
- Bordetella Pertussis or whooping cough (rare) must be excluded from the diagnosis.
If the cough is not caused by whooping cough or sinusitis, your doctor will likely prescribe a combination of inhalers, oral steroids to decrease the inflammation, and cough suppressants.
What if I have a chronic cough?
A chronic cough can be a diagnostic challenge for your healthcare provider. The causes can include problems with the nose, nasopharynx, the rest of the airways, and even the gastrointestinal tract.
Obvious causes of a chronic cough can include smoking, or the use of certain antihypertensive medications called angiotensin-converting enzyme (ACE) inhibitors.
Those patients who fit into either of these categories must stop the offending agent and the cough usually resolves. The exception, of course, is smoking if there has been long-term lung damage causing COPD or emphysema.
There are three main categories of conditions used to describe the causes of chronic cough:
Upper airway cough syndrome (previously known as postnasal drip syndrome) refers to the secretions from the nose or sinuses that drain down into the throat in addition to nasal discharge and frequent throat clearing. The patient’s physical examination is usually normal. In fact, at least 20% of patients who suffer from this condition do not always link it to their cough.
Asthma involves variable airflow obstruction and airway hyper-responsiveness. This leads to shortness of breath, wheezing, and cough.
All asthmatics suffer from coughing at some point. There are some patients who have cough-variant asthma. This means cough is their only symptom and the treatment is the same as all other variations of asthma.
A majority of patients respond to treatment. If they do not, they may have nonasthmatic eosinophilic bronchitis. This is diagnosed using an induced-sputum test to determine if the patient has an increased number of eosinophils.
Eosinophils are a kind of white blood cell that fights disease. They can be elevated in number with an allergic response or with an infection or inflammation. Most patients with nonasthmatic eosinophilic bronchitis and cough have a resolution of their symptoms within a month of using a steroid inhaler.
Gastroesophageal reflux disease. Gastroesophageal disease may affect the lower and upper parts of the esophagus. It differs from traditional gastroesophageal disease since the person may not suffer from heartburn and the coughing tends to occur when the person is upright. This silent gastroesophageal reflux can be present in three-quarters of patients with a chronic cough.
Diagnosis may include 24-hour esophageal pH monitoring, a barium swallow, or a high-resolution CT scan.
Treatment may be the same as standard gastroesophageal disease, including lifestyle and dietary modification, and medications to either suppress gastric acid production or protect the stomach and esophagus. Surgery is a last resort.
It is hard to tell if a cough is serious. The best course of action is to be evaluated by a healthcare professional, particularly if it is one component of a combination of other signs or symptoms.
The bottom line is that although a cough is a natural physiological reflex, it is usually indicative of more than just the cough itself.
Uncommon causes of cough can include everything from congestive heart failure to a swallowing disorder or sinusitis.
Most primary care physicians can diagnose and treat coughs.
In some cases, the patient needs to be referred to a cough specialist who may be a pulmonologist, ENT, or gastroenterologist.
Mayo Clinic. Cough.
WebMD. Cold and Flu.
Cleveland Clinic. Cough.