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.

Source: http://www.mayoclinic.com

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

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.

Source: http://www.mayoclinic.com

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.
• 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.
• Chronic bronchitis. This long-standing inflammation of your major airways (bronchial tubes) can cause a cough that brings up colored sputum. Most people with chronic bronchitis are current or former smokers. Chronic bronchitis is usually part of the spectrum of smoking-related lung disease called chronic obstructive pulmonary disease (COPD). Emphysema is also incorporated under this term, and chronic bronchitis and emphysema often coexist in current or former smokers with COPD.

Less commonly, chronic cough may be caused by:

• Aspiration (food in adults; foreign bodies in children)
• Bronchiectasis (damaged airways)
• Bronchiolitis
• 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)

Source: http://www.mayoclinic.com

Diagnosis

Your doctor will ask about your medical history and perform a physical exam. 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 cough or your sinus cavities for pockets of infection.

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.

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 colored, 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 use a thin, flexible tube equipped with a light and camera. With a 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.

With a rhinoscope, your doctor can view your nasal passages to look for upper airway causes of cough.

Children

A chest X-ray and spirometry, at a minimum, are typically ordered to find the cause of a chronic cough in a child.

Source: http://www.mayoclinic.com

Complications

Having a persistent cough can be exhausting. Coughing can disrupt your sleep and cause a variety of other problems, including:

• Headache
• Dizziness
• Excessive sweating
• Loss of bladder control (urinary incontinence)
• Fractured ribs
• Passing out (syncope)

Lifestyle and home remedies

Follow the plan your doctor gives you for treating the cause of your cough. In the meantime, you can also try these tips to ease your cough:

• Drink fluids. Liquid helps thin the mucus in your throat. Warm liquids, such as broth, tea or juice, can soothe your throat.
• Suck on cough drops or hard candies. They may ease a dry cough and soothe an irritated throat.
• Moisturize the air. Use a humidifier or take a steamy shower.
• Avoid tobacco smoke. Smoking or breathing second-hand smoke irritates your lungs and can worsen coughs caused by other factors. If you smoke, talk with your doctor about programs and products that can help you quit.

Source: http://www.mayoclinic.com

Risk factors

Being a current or former smoker is one of the leading risk factors for chronic cough. Frequent exposure to secondhand smoke also can lead to coughing and lung damage.

Women tend to have more-sensitive cough reflexes, so they're more likely to develop a chronic cough than are men.

Source: http://www.mayoclinic.com