What Does a Persistent Cough Mean?

Is your cough something to worry about? Everyone picks up a cough from time to time, but when that cough lingers on for more than two weeks, alarm bells may start sounding in your head. Here’s how to know what your persistent cough could be mean.

What is a persistent cough a sign of?

A persistent cough can by a symptom of bronchitis (aka “chest cold”), asthma and chronic obstructive pulmonary disease (COPD), postnasal drip, smoking of any kind, occupational triggers, allergies, gastro-esophageal reflux disease, medication side effects, pneumonia or bronchiectasis, or something more serious such as lung cancer or tuberculosis.

The severity and “type” of the cough, can indicate exactly what the cause is. For example, characteristics of the cough such as the production of phlegm (vs a dry cough), the association with location (home, work, outdoors), and the association with the time of day (morning, night, after eating etc.) can begin to help doctors narrow down the possibilities.

According to the American College of Chest Physicians and the American Academy of Family Physicians, the most common causes of persistent cough in children and adults are:

Postnasal Drip

This is when the nose and sinuses produce extra mucus. The excess mucus drips down the back of the throat and triggers the cough reflex. You may or may not have runny nose or itchy eyes. If your cough occurs around allergy season, this could be the reason.

Acid Reflux

For some people, acid reflux may not occur with heartburn, and instead the only indicator will be a persistent cough. A persistent cough due to acid reflux usually gets worse at night after lying down in bed.


An asthma related cough may also be consistent with the changing seasons. Cough variant asthma (CVA) is a form of asthma that is characterized by a chronic, dry (non-productive) cough. It is considered by some to possibly be an early sign of “classic” asthma where a cough may be the first sign of several symptoms yet to come.


For infections, such as the common cold, flu, bronchitis or pneumonia, a cough can linger. The most common cause of these infections are viruses and, in many cases, it could take 3 weeks for symptoms to completely disappear. Unfortunately, antibiotics do not reduce the duration of symptoms and may cause adverse side effects like diarrhea, vomiting, antibiotic resistance, or a dangerous intestine infection called Clostridium Difficile. One rare infection caused by a bacteria is whooping cough (pertussis). This can cause a persistent cough in both children and adults.

What can cause a cough to last for months?

A cough is considered chronic or persistent when it lasts longer than 8 weeks in adults or 4 weeks in children. While smoking is a leading cause, there are many other possible reasons. In some cases, it could be caused by heart or lung disease. Your doctor may order radiological images, lung function testing or perform additional blood tests.

Is persistent cough a sign of cancer?

While possible, lung cancer is the cause for less than 2% of people with a persistent cough. Chronic cough may also be the result of tumors in the chest such as lymphomas or lung metastases from other cancers.

What can you do at home?

Whether you’ve decided to make an appointment or wait it out, it’s important to do what you can to ease the symptoms to avoid hurting your lungs and throat. Try these tips to help ease your cough at home:


Honey, as an antioxidant, has many properties which help reduce inflammation produced by many viruses. For anyone older than 1 year of age, one teaspoon of honey 1-2 times a day helps reduce the frequency and severity of cough. It may also help improve sleep.


Liquid can help to thin the mucus in your throat and improve the function of your immune system. Warm liquids such as tea or broth can open up your airways and help the mucus more easily move.


Using a humidifier or running a hot and steamy shower can also help to open up airways and loosen mucus.

Avoid Tobacco/Caffeine/Alcohol

Caffeine, alcohol and tobacco (diuretics) will clear out the water you have in your body, drying up your airways and allowing mucus to become thicker. Try to avoid tobacco smoke and drinking alcohol or caffeine.

Cough Drops

Cough drops are another solution that may offer safe and temporary relief for your dry or congested throat. The menthol in cough drops helps cool the airway passages and lubricate irritated throat tissue. If you are pregnant, consult your doctor before taking over the counter medication. Children younger than 4 years old should not be given over the counter cough or cold medicine.

If you have a persistent cough that is interfering with your day to day activity or if your cough is getting worse, contact Valleywise Health today. Our primary care physicians are friendly, knowledgeable and ready to assist you.

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3345522/
2. https://breathe.ersjournals.com/content/7/2/122
3. https://www.aafp.org/afp/2016/0701/p20.html
4. https://www.choosingwisely.org/societies/american-academy-of-pediatrics/

About the Author

Androuw Carrasco, MD - Family Medicine

Androuw Carrasco, MD, is a District Medical Group physician at Valleywise Health. He currently practices Family Medicine at Valleywise Community Health Center - 7th Avenue. He studied medicine at Michigan State University. Dr. Carrasco completed his residency at University of Arizona Family and Community Medicine in Tucson, AZ. He completed a fellowship in Global Health Medicine at Contra Costa Regional Medical Center in Martinez, CA. He is board-certified by the American Board of Family Medicine. ​

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