All about coughs and their causes

 

 A cough, also known as tussis, is a voluntary or involuntary act that clears 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 as part of a reflex. 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.

Fast facts on coughs

Here are some key points about coughs. More detail and supporting information is in the main article.

•            Some germs use coughing to spread to new hosts.

•            There is a wide array of potential causes of coughs.

•            Some types of cough only occur 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?

 possible causes.

1.           Inhalation (breathing in).

2.           Increased pressure in the throat and lungs with the vocal cords closed.

3.           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. We look at some potential causes in the next section.

Causes

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 or URI (upper respiratory tract infection). Examples include:

•            flu

•            common cold

•            laryngitis

If it is an LRTI (lower respiratory tract infection), the lungs are infected, and/or the airways lower down from the windpipe. Examples include:

•            bronchitis

•            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 (post nasal drip)

•            GERD (gastro-esophageal reflux disease)

•            asthma

•            some medications (e.g., ACE inhibitors)

Chronic coughs in children are most often caused by asthma, but can also be from conditions like post-nasal drip or 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, it is sensible to visit a doctor.

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.

•            Difficulty swallowing.

•            Permanent changes in the sound of the voice.

•            Coughing up blood.

•            Difficulty breathing.

•            Chest pain.

•            Fevers that are not getting better.

 

Overview

A chronic cough is a cough that lasts eight weeks or longer in adults, or four weeks in children.

A chronic cough is more than just an annoyance. A chronic cough can interrupt your sleep and leave you feeling exhausted. Severe cases of chronic cough can cause vomiting, lightheadedness and even rib fractures.

While it can sometimes be difficult to pinpoint the problem that's triggering a chronic cough, the most common causes are tobacco use, postnasal drip, asthma and acid reflux. Fortunately, chronic cough typically disappears once the underlying problem is treated.

Symptoms

A chronic cough can occur with other signs and symptoms, which may include:

•            A runny or stuffy nose

•            A feeling of liquid running down the back of your throat (postnasal drip)

•            Frequent throat clearing and sore throat

•            Hoarseness

•            Wheezing and shortness of breath

•            Heartburn or a sour taste in your mouth

•            In rare cases, coughing up blood

Causes

An occasional cough is normal — it helps clear irritants and secretions from your lungs and prevents infection.

However, a cough that persists for weeks is usually the result of a medical problem. In many cases, more than one cause is involved.

The following causes, alone or in combination, are responsible for the majority of cases of chronic cough:

•            Postnasal drip. When your nose or sinuses produce extra mucus, it can drip down the back of your throat and trigger your cough reflex. This condition is also called upper airway cough syndrome (UACS).

•            Asthma. An asthma-related cough may come and go with the seasons, appear after an upper respiratory tract infection, or become worse when you're exposed to cold air or certain chemicals or fragrances. In one type of asthma (cough-variant asthma), a cough is the main symptom.

•            Gastroesophageal reflux disease (GERD). In this common condition, stomach acid flows back into the tube that connects your stomach and throat (esophagus). The constant irritation can lead to chronic coughing. The coughing, in turn, worsens GERD — a vicious cycle.

•            Infections. A cough can linger long after other symptoms of pneumonia, flu, a cold or other infection of the upper respiratory tract have gone away. A common but under-recognized cause of a chronic cough in adults is pertussis, also known as whooping cough. Chronic cough can also occur with fungal infections of the lung, tuberculosis (TB) infection or lung infection with nontuberculous mycobacterial organisms.

•            Chronic obstructive pulmonary disease (COPD). COPD, a chronic inflammatory lung disease that causes obstructed airflow from the lungs, includes chronic bronchitis and emphysema. Chronic bronchitis can cause a cough that brings up colored sputum. Emphysema causes shortness of breath and damages the air sacs in the lungs (alveoli). Most people with COPD are current or former smokers.

•            Blood pressure drugs. Angiotensin-converting enzyme (ACE) inhibitors, which are commonly prescribed for high blood pressure and heart failure, are known to cause chronic cough in some people.

Less commonly, chronic cough may be caused by:

•            Aspiration (food in adults; foreign bodies in children)

•            Bronchiectasis (damaged, dilated airways)

•            Bronchiolitis (inflammation of the very small airways of the lung)

•            Cystic fibrosis

•            Laryngopharyngeal reflux (stomach acid flows up into the throat)

•            Lung cancer

•            Nonasthmatic eosinophilic bronchitis (airway inflammation not caused by asthma)

•            Sarcoidosis (collections of inflammatory cells in different parts of your body, most commonly the lungs)

•            Idiopathic pulmonary fibrosis (chronic scarring of the lungs due to an unknown cause)

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)