Coughs: Causes, Symptoms, and Treatments
A cough, also known as tussis, is a sudden reflex that humans and many animals have. Its purpose is to clear the throat and breathing passage of foreign particles, microbes, irritants, fluids, and mucus – it is a rapid expulsion of air from the lungs.
Coughing can be done deliberately or involuntarily. Although coughing can be a sign of a serious illness, more often, it will clear up on its own without the need for medical attention.
In this article, we will cover the causes, diagnosis, and treatments for coughs.
Fast facts on coughs
Here are some key points about coughs. More detail and supporting information is in the main article.
- Germs use coughs to spread to new hosts
- There is a wide array of potential causes of coughs
- Some types of cough only present at night
- If the cough is difficult to diagnose, a chest X-ray may be necessary
- Home remedies can soothe the majority of coughs
What is a cough?
There are three phases to a cough reflex:
- An inhalation (breathing in)
- An increased pressure in the throat and lungs with the vocal cords closed
- An explosive release of air when the vocal cords open, giving a cough its characteristic sound
If somebody coughs a lot, it can be a sign of a disease. Many coughs are caused by infectious diseases, like the common cold, but there are also non-infectious causes.
Coughs can be due to pollution/irritation, GERD (gastroesophageal reflux disease), choking, chronic bronchitis, asthma or emphysema, a tumor in the lung, heart failure, some drugs (e.g., ACE inhibitors), post-nasal drip, and smoking.
A doctor will focus on treating the cause of the cough; for example, if it is due to an ACE inhibitor, it may be discontinued. Codeine, dextromethorphan, and other cough suppressants are often used by people with coughs. However, there is not much research into cough medicines and how much they can actually reduce symptoms.
Classification of coughs
- Acute cough– has a sudden onset and lasts up to 3 weeks
- Subacute cough– persists for 3-8 weeks
- Chronic cough– persists for over 8 weeks
- Productive cough– a cough that brings stuff up, such as sputum
- Dry cough– a cough that brings nothing up
- Nocturnal cough– only occurs at night
Causes of coughs
The majority of coughs are caused by viruses and clear up without treatment.
Causes of acute (short-term) cough – in most cases, the infection is in the upper respiratory tract and affects the throat, this is known as a URTI/URI (upper respiratory tract infection). Examples include flu, the common cold, and laryngitis.
If it is an LRTI (lower respiratory tract infection), the lungs are infected, and/or the airways lower down from the throat (windpipe). Examples include bronchitis and pneumonia.
An acute cough can also be caused by hay fever.
Causes of chronic (long-term) cough – a chronic cough may be caused by smoking, mucus dripping down the throat from the back of the nose (nasal drip), GERD (gastro-esophageal reflux disease), asthma, and some medications (e.g. ACE-inhibitors).
Chronic coughs in children are most often caused by asthma, but can also be from conditions like GERD.
Less common causes of chronic cough in adults include TB (tuberculosis, fungal infections of the lung, and lung cancer.
When to see a doctor
If a cough has persisted for 3 weeks without improvement, a doctor’s advice should be sought. In most cases, there will not be anything serious underlying the cough, but in rare cases, a long-term cough can be a sign of something that needs treating, such as lung cancer or heart failure.
Other reasons to seek medical advice include:
- The cough is getting worse
- There are swelling or lumps present in the neck region
- Weight loss
- Severe coughing
- Changes in the sound of the voice
- Coughing up blood
- Difficulty breathing
- Chest pain
- Fevers that are not getting better
Diagnosing a cough
If a doctor decides that a cough is caused by the common cold or flu, the general advice will be to rest, drink plenty of fluids, and let it run its course. In the majority of cases, such coughs clear up after 1-2 weeks.
A cough caused by a viral infection that persists for more than a couple of weeks will probably require medical attention.
The doctor may order some diagnostic tests, such as a chest X-ray, a sample of phlegm may be sent to a laboratory for analysis to determine what is causing the infection.
The patient may be asked to breathe in and out of a tube attached to a machine; this helps the doctor determine whether the airways have an obstruction (this test is called a spirometry), which is common in asthma or emphysema.
If asthma is diagnosed, the patient may be prescribed asthma medication.
Sometimes, a doctor may refer the patient to a respiratory specialist.
Treatments and home remedies for coughs
The best way to treat a cough caused by a viral infection is to let the immune system deal with it – generally, such coughs clear up on their own. According to the National Health Service, United Kingdom, a homemade remedy with honey and lemon is as good, if not better than most OTC products sold in pharmacies.
Treatments are mostly aimed at making the patient feel a little bit better and generally do not decrease the length of the cough.
Honey – it coats the throat, resulting in less irritation and possibly less coughing. Honey is a demulcent (something that soothes).
Cough medications – some may help associated symptoms, such as fever or a stuffy nose. However, there is no compelling evidence that cough medicines are effective in making the cough go away faster.
For small children, it is a good idea to talk to a doctor before giving OTC cough medicine. Some ingredients in cough medicines can be dangerous for small children.
Cough suppressants – these suppress the cough reflex and are generally only prescribed for a dry cough. Examples include pholcodine, dextromethorphan, and antihistamines.
Expectorants – these help bring up mucus and other material from the trachea, bronchi, and lungs. An example is guaifenesin (guaiphenesin), which thins the mucus and also lubricates the irritated respiratory tract, helping to drain the airways.
Advertisemen
and Treatments Causes Cough medications Cough suppressants Coughs Diagnosing a cough fever Homeopathy Symptoms
