MANILA, Philippines - For many people, a chronic cough - one lasting eight weeks or longer - is much more than an annoyance. In addition to being physically draining, a cough that hangs on for months can alienate your family and co-workers, ruin your sleep, and leave you feeling angry and frustrated. For a condition that may be relatively minor, a chronic cough can have major repercussions.
Part of the problem is that unlike the cough you get with a cold or the flu, the reason for a chronic cough isn't always clear. Even after repeat office visits and numerous tests, the cause can remain elusive. Still, the majority of cases can be diagnosed. Postnasal drip, asthma and acid reflux cause most chronic coughs; less often, infections or medications are to blame.
Although a chronic cough may not be a symptom of a serious condition, it's important to investigate any cough that doesn't go away. If the reason for a chronic cough can't be found, your doctor may prescribe a cough suppressant or other medications to help manage your symptoms
A chronic cough can occur with other signs and symptoms, which may include:
* A runny or stuffy nose
* A sensation of liquid running down the back of your throat
* Wheezing and shortness of breath
* Heartburn or a sour taste in your mouth
* In rare cases, coughing up blood
A cough begins when an irritant - stomach acid, mucus, hair spray, perfume, even spicy food - stimulates nerves in your respiratory tract. The cough impulse travels to your brain, which then signals muscles in your stomach and diaphragm to give a strong push to air in your lungs. It takes such force to expel irritants that the speed of coughed air can approach 500 miles an hour.
An occasional cough is normal - it helps clear foreign substances and secretions from your lungs and prevents infection. But a cough that persists for long periods of time is usually the result of an underlying problem, such as:
* Postnasal drip. Every day, glands in your nose and throat produce a quart or two of mucus, which cleans and moisturizes your nasal passages. Normally, you swallow the fluid without knowing it, but when there's more than usual - from allergies, a cold or sinus infection - you may feel it accumulating in the back of your throat. This excess mucus, commonly called postnasal drip, can cause irritation and inflammation that trigger your cough reflex. If the postnasal drip is chronic, your cough is likely to become chronic, too. Though postnasal drip is often obvious, it's possible to have the condition without ever having symptoms.
* Asthma. This is a common cause of chronic cough in adults and the leading cause in children. Most often, the cough occurs with wheezing and shortness of breath, but in one type of asthma, cough is the only symptom. 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.
* 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 in your esophagus, throat and even your lungs can lead to chronic coughing. Acid reflux often causes heartburn and a sour taste, yet close to half the people whose cough is due to reflux have no symptoms.
* Respiratory tract infection. A cough can linger long after most symptoms of a cold, flu, pneumonia or other infection of the upper respiratory tract have gone away. This may be because the airways remain inflamed and therefore especially sensitive to irritants.
* 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 …