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15 Common Reasons Behind That Stubborn Cough

6 min read

By Emily Lockhart

Medically Reviewed by Dr. Gerald Morris

Is an incessant cough keeping you up at night, causing you a tight chest, or causing mucus buildup? Seasonal allergies, the flu virus, or some kind of lung infection are the most common reasons for a nagging cough. However, a cough can sometimes indicate a more serious health condition, such as asthma. Whatever the reason for your hacking, a cough is the body’s typical reflex when foreign material is blocking the lungs and upper airway passages.

So, how do you determine one cough from another? Let’s take a look at why a cough occurs, and what the top common health conditions a cough indicates, depending on the associated symptoms of course. 15 common reasons behind that stubborn cough are…

1. Post Nasal Drip

Post-nasal drip (phlegm or mucus draining down the back of the throat from the sinus cavities) is a very common source of an itchy, scratchy cough that you’d get with seasonal allergies. Those with allergies, commonly experience post-nasal drip during periods of high pollen, such as ragweed season in the late summer/early fall.

2. The Common Cold or Flu

The common cold or seasonal flu is most often caused by a viral infection of the nasal passages, which causes mucus build-up in the nose, throat, and sometimes the chest, which again, drains down the back of the throat, similar to post-nasal drip, but is caused by the infection of the sinuses, lungs, or upper airways, and not simply allergies. If left untreated, a case of the flu can quickly turn into a more serious case of pneumonia, bronchitis, or sinusitis.

3. Smoking

Smoking cigarettes, cigars, or pipe tobacco will often cause a nagging cough in the smoker due to an irritation of the lungs, esophageal lining, or the throat. Smoking, more specifically nicotine and the chemical ingredients in tobacco, is closely linked to lung irritation and eventually, over long-term use, lung damage.


Gastroesophageal reflux disease (GERD) or acid reflux, is a chronic condition that results when the stomach acid damages the linings of the throat and esophagus. This damage occurs when acid sprays up from the stomach into the esophagus and causes irritation and coughing to occur. GERD can be exacerbated during sleep (or whenever the patient is lying prone) when gravity doesn’t help keep stomach acid down. GERD sufferers can get better sleep if they prop their head up on a pillow to help aid drainage and keep stomach acid under control.

5. Bronchial Illness or Infection

A dry, hacking cough can occur at the tail end of a cold or influenza, particularly if it’s left untreated for several weeks. Bronchitis occurs when the mucous membranes in the airways linking the trachea to the lungs (or bronchi) become inflamed and irritated. The telltale symptom of a bronchial condition is bronchospasm (a restriction of airflow in the lungs), which may cause wheezing.

6. Asthma

This chronic inflammatory condition of the airways characterized by a recurring cough, wheezing, tight chest, and shortness of breath caused by a restriction of airflow in the lungs. This ever-present dry, wheezing cough may worsen after physical exertion (such as walking up stairs or exercise). A prescription inhaler can help reduce chest tightness and promote better airflow.

7. Environmental Dust or Chemicals

The breathing in of dust, chemicals, or fumes in any environment can cause the onset of a cough. Most typical to work environments, exposure to dust particles or irritating fumes will irritate the airways and result in a feeling that you constantly need to clear your throat in order to rid the body of toxic substances.

8. Lung Disease

Chronic lung disease, either hereditary or due to tissue lung damage (most often smoking) will be accompanied by a stubborn cough. Incessant coughing is a common symptom of chronic lung diseases, such as chronic obstructive pulmonary disease (COPD), which is caused by smoking, as well as bronchopulmonary dysplasia (BPD), which causes tissue damage in the lungs of newborn babies. Both chronic conditions cause lung restriction, collapse, mucus buildup, and stubborn coughing.

9. Medications

Certain prescription medications, particularly angiotensin converting enzyme (ACE) inhibitors (which doctors prescribe to control high blood pressure), can result in a chronic cough in long-term users of the medication. The cough is thought to result from a buildup of substances in the lungs. The good news is the cough will subside with the discontinuation of the causative ACE inhibitor, after discussion with a doctor.

10. Blocked Airways

The most obvious cause of a cough in a small child or diner at a restaurant is a blocked airway. This may occur if a child accidentally inhales an object, such as a piece of a toy or a large chunk of food. Airway blockage can also occur if a children or adult with a small airway swallows a pill whole.

11. Pneumonia

As mentioned earlier, pneumonia sometimes occurs after a common cold or flu lingers instead of going away. However, this is not always the case, as it can be caused by contracting any number of viruses, bacteria, or fungi.

A cough is the most common symptoms of this serious respiratory tract infection, one that tends to produce mucus that is green or reddish in color. This cough may persist for weeks after the pneumonia has been treated with antibiotics and all other symptoms have disappeared. A nagging cough is also a typical sign of “walking pneumonia,” a form of pneumonia that tends to affect people 40 years of age or younger.

12. Tuberculosis

More seriously, a persistent cough may be an indication of tuberculosis (or, more specifically, active tuberculosis, as those with latent tuberculosis do not tend to exhibit symptoms). It tends to last for 2-weeks or longer and may sometimes cause you to produce blood or phlegm.

Tuberculosis primarily affects people in developing countries—especially those who smoke, are malnourished, or have compromised immune systems—but it can affect people of any age, anywhere in the world. Most cases of tuberculosis can be cured with antibiotics, although they often need to be taken for a lengthy period of time (approximately 6 months or more).

13. Laryngitis

A chronic cough can also point to laryngitis, which the Mayo Clinic defines as “inflammation of your voice box (larynx) from overuse, irritation, or infection.” It causes the vocal cords to be come swollen, which compromises the sound of your voice.

In comparison to some of the other conditions on this list, the cough associated with laryngitis does not produce mucus or phlegm; it tends to be very dry. Although the source says the cough (as well as the other symptoms of laryngitis) tend to clear up within a couple of weeks, if they happen to last longer than that or you notice you’re coughing up blood, it’s important to seek medical attention immediately.

14. Whooping Cough

As its name implies, the most characteristic symptoms of whooping cough (also known as pertussis) is, well, a cough. This isn’t like any old cough though. describes it as “a violent cough that can make breathing difficult.” And the distinctive whooping sound comes from “attempting to inhale air into the lungs between coughs.”

This cough can last for several weeks, even after other symptoms have waned. Although the source reports that, “pertussis is still a relatively uncommon cause of chronic cough,” there has been a recent increase in cases in the United States, which may be due to inadequate vaccinations against the bacterial disease.

15. Heart Failure

Although they may seem unrelated, coughing and shortness of breath are common symptoms of heart failure. They occur because the weakened heart allows a build up of fluid in the lungs.

Harvard Medical School indicates the cough associated with heart failure tends to be at its worst when the affected individual is lying flat, such as when sleeping. As a result, “they often resort to sleeping propped up on three or four pillows,” says the source. For some, the cough may be dry in nature, while it may produce “thin, frothy white sputum” in others.

MD, Family Medicine, Internal Medicine

Gerald Morris, MD is a family medicine/internal medicine physician with over 20 years expertise in the medical arena. Dr. Morris has spent time as a clinician, clinical research coordinator/manager, medical writer, and instructor. He is a proponent of patient education as a tool in the diagnosis and treatment of acute and chronic medical conditions.

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