Everyone has gotten a cough at some point in their life. After all, it’s one of the most common symptoms of an illness like the common cold. In these cases, your cough will usually start improving in a couple of days, and after a week or two, it’s gone.

But what if you developed a cough several weeks or even a few months ago, and it won’t go away? You may start to wonder, “Can a chronic cough be serious?”

The good news is that a long-lasting or chronic cough usually isn’t serious and can go away on its own. But depending on the underlying cause of the cough, getting an official diagnosis from a doctor and starting a treatment plan is key to getting relief.

So, what may be causing your cough? And when should you see a doctor? Below, we answer these questions and more.

First, what’s considered a chronic cough?

Most coughs go away on their own with home treatments – usually within a couple weeks. But when they stick around for more than four weeks in children or more than eight weeks in adults, they’re considered chronic or persistent.

So, why are you coughing so much? These are some of the common causes of chronic coughing

A chronic cough is usually a sign that something’s bothering one or more parts of your respiratory system – it could be your nose, sinuses, throat, airway tubes or lungs.

There are many different conditions that have a chronic cough as a possible symptom. It’s also possible that there may be more than one reason for your chronic cough. Generally speaking, causes of chronic coughs can be grouped into a few general categories:

Certain substances can irritate your respiratory system, causing a persistent dry cough

The air we breathe often contains things like smoke, pollution, dust, mold, pollen or chemicals. And for some people, these substances can cause an allergic reaction. For others, even clean air that’s too cold or too dry can also cause chronic coughs. Chronic coughs caused by an irritated respiratory system are usually dry.

Allergies

A cough is one of the common symptoms of allergies. (Other symptoms include itchy, watery eyes and a runny nose.) If your allergies stick around for a long time, you could end up with a chronic cough.

Allergies happen because your body’s immune system reacts to harmless substances, like pollen or cat hair, as if they were dangerous and attack them. There are many treatment options for allergies, and your primary care doctor can help you figure out what might work for you.

Asthma

Asthma is a condition in which your airways become inflamed and narrow in response to certain triggers. Common symptoms of asthma are wheezing, trouble breathing and tightness in your chest. Asthma doesn’t always cause coughing. Sometimes, the coughing is so severe that it leads to coughing fits.

Some people are more likely to have asthma attacks during allergy season.  Asthma attacks can also be triggered by cold air, exercise, chemicals and fragrances.

There are effective treatments for asthma, including inhalers and over-the-counter nasal sprays like Flonase. If you think you or your child may have asthma, make an appointment with a primary care doctor or clinician. Primary care doctors can diagnose and treat hundreds of conditions, including asthma. They can also refer you to an asthma specialist if needed.

Postnasal drip

Postnasal drip is when the mucus in your nose or sinuses drips down the back of your throat. The mucus can tickle the nerves at the back of your throat, causing a chronic cough. Postnasal drip is a common cause of a sore throat and can make it difficult to swallow.

Postnasal drip is often related to a cold or seasonal allergies. But it can also be caused by bacterial infections, a deviated septum, medications or if there’s an object stuck in your nose.

If you think your chronic cough is from postnasal drip, it’s a good idea to talk to your primary care doctor. They can help uncover the cause of your postnasal drip and offer possible treatments.

Cigarette smoke

Cigarette smoke is a common cause of a dry cough. Plus, smoking and secondhand smoke can make a cough worse, no matter the cause.

Infections can cause different types of coughs

A cough is one of the most common symptoms of a respiratory infection. How long a cough lasts can depend on the cause and location of the infection. Infections in the upper respiratory system (throat and sinuses) tend to go away more quickly than those in the lower respiratory system (airway and lungs). And it’s usually easier to get over a viral infection than a bacterial infection.

If you have a chronic wet cough and it feels like you’ve been coughing up mucus for weeks, it may be a sign you have a bacterial infection that needs to be treated. It’s generally a good idea to talk to your doctor if you have a persistent cough with phlegm.

The other thing to know is that you can have a lingering cough, even after the infection is gone. That’s because your body may need time to get rid of the damage and inflammation that happened while you were sick.

Common cold

A wet, hacking cough is a common cold symptom, but coughs can also be dry. Usually, your body is able to fight off the cold virus in about a week. Your cough may linger because your throat is irritated from the cold virus – and, unfortunately, coughing can increase airway irritation. While it’s not common, it is possible for a cough to stick around for several weeks after a cold.

Sinus infections

There are viral and bacterial types of sinus infections. The main symptom is a stuffy nose that won’t go away – this can lead to facial pain and headaches. But a cough is another possible symptom. Sometimes, sinus infections turn into chronic sinusitis, leading to a cough and other symptoms that stick around for months.

COVID-19

A cough is one of the most common symptoms of COVID-19. A chronic cough is also a long-COVID lung symptom that can last for months after you no longer have COVID-19.

Coughs can sound very different depending on the variant of COVID-19 and the age of the person who gets it. For example, the Omicron variant of COVID-19 is reported to cause a barking cough in children under 5 years old.

Bronchitis

If you have bronchitis, it means that there’s inflammation in the bronchial tubes that carry air into your lungs. The main symptom of bronchitis is a cough. In the beginning, it’s usually a dry cough, but over time, it can turn into a wet cough with a lot of phlegm. In some cases, bronchitis causes violent coughing fits (paroxysmal coughing).

Bronchitis is usually caused by a virus, and usually goes away without treatment in a few weeks. However, it’s possible for bronchitis to turn chronic, especially in people who smoke. In some cases, bronchitis can turn into pneumonia or chronic obstructive pulmonary disease (COPD).

Pneumonia

Pneumonia is when your lung tissue gets infected by bacteria, viruses or fungi. This causes inflammation of your lung tissue and fluid buildup in the air sacs in your lungs.

A cough is one of the most common symptoms of pneumonia. Often these coughs have a distinct sound – like a rattle with a wheezing or whistling sound. They can also be pretty loud. The cough may be a dry cough or a cough that produces thick yellow, green, brown or blood-stained mucus. Pneumonia can also cause violent coughing fits.

Croup

A barking cough is the most noticeable symptom of croup, an infection that causes swelling and irritation around the voice box, windpipe and bronchial tubes. Croup is most common in kids between 3 months and 5 years old.

At first it may seem like your child has a cold with a stuffy or runny nose but, as the swelling gets worse, they may have difficulty breathing or a hoarse voice. Croup usually goes away in a couple days, but it can last for a few weeks. It’s also possible for the cough to last after the infection is gone.

Whooping cough

Whooping cough causes a chronic cough. This infection is caused by an incredibly contagious type of bacteria called Bordetella pertussis. Anyone can get whooping cough, but the symptoms tend to be more serious in young babies under the age of 6 months old.

Whooping cough can start out like a cold, but the cough sticks around much longer. In the beginning, your cough is likely to be dry. After a week or so, you may start having violent coughing fits which can last up to 10 weeks. If it’s whooping cough, you will likely have a runny nose, nasal congestion, red or watery eyes, and a slightly elevated temperature.

A vaccine for whooping cough is part of the recommended childhood immunization schedule. While you can get whooping cough after having the vaccination, you probably won’t get as sick.

Tuberculosis

Tuberculosis (TB) is a serious bacterial infection that mainly affects your lungs. One of the first symptoms of active tuberculosis is a cough that lasts for more than three weeks. It can start as a dry, irritating cough but may turn into a productive cough that brings up blood or mucus. At times, TB can cause coughing fits. Other symptoms of TB include chest pain, weakness, unexplained weight loss, fever and night sweats.

TB is extremely rare in the United States, but it’s more likely in people with weakened immune systems, such as those living with HIV/AIDS.

Medical conditions can cause a cough that won’t go away

A chronic cough can be caused by medical conditions that affect your ability to breathe, circulate blood and control the amount of mucus in your lungs. These conditions include:

Acid reflux

Acid reflux is when your stomach acid flows up into your esophagus (the tube connecting your stomach and throat). The stomach acid can trigger cough receptors which are present in the esophagus as well as the airways.  Acid reflux is one of the most common causes of chronic cough.

If your cough is caused by acid reflux, you may also have heartburn, chest pain, chronic sore throat and mild hoarseness. You may feel like you have a lump in the back of your throat that makes it difficult to swallow, and you may spit up food or sour liquid.

You may be able to manage occasional bouts of acid reflux with antacids, but if you have symptoms more than twice a week, make sure to talk to your doctor about possible treatments. It could be that you need treatment for chronic acid reflux (also called gastroesophageal reflux disease or GERD).

Chronic obstructive pulmonary disease

COPD is a group of lung diseases that make breathing difficult and gradually worsen over time. COPD includes chronic bronchitis and emphysema.

The main symptom of COPD is a chronic cough. It’s common to cough up colored mucus. COPD usually happens in people who have a history of smoking, but it can also follow long-term exposure to lung irritants like secondhand smoke or air pollution.

Certain blood pressure medications

Angiotensin-converting enzyme (ACE) inhibitor medications, which are commonly prescribed to manage high blood pressure and heart failure, have been linked to chronic cough.

Heart failure

When someone has heart failure, it means that their heart isn’t working as well as it should be – and it’s more common in people with other heart conditions. A chronic dry cough can be a symptom of heart failure, but the condition can also cause a cough with foamy white or pink-tinted mucus. Other symptoms include fatigue and weakness, abdominal swelling and shortness of breath.

Lung cancer

Cancer is a disease where your body’s cells grow out of control. Lung cancer is when the disease begins in the lungs. A chronic dry cough is common with lung cancer. Shortness of breath, chest pain, unintended weight loss, bone pain, headaches and spitting up blood are other symptoms of lung cancer.

Lung cancer is usually caused by cigarette smoke. It is also one of the deadliest cancers in the United States. Getting screened for lung cancer can help catch it earlier when it’s more treatable.

Other conditions that can cause a chronic cough

There are several other medical conditions that can cause chronic coughs, but these conditions are typically uncommon or very rare.

  • Collapsed lung – Collapsed lungs are most common after a traumatic event such as a car accident or puncture wound to the chest. It’s possible for a lung to collapse on its own, but this is extremely rare – especially if no other underlying lung conditions are present.
  • Pulmonary fibrosis – Pulmonary fibrosis is an uncommon but serious lung disease that causes scarring in the lungs and changes how a person breathes and gets oxygen. While a chronic dry cough is often the first symptom, it can also cause problems such as breathing, unintended weight loss, tiredness and muscle aches.
  • Cystic fibrosis – Cystic fibrosis is a genetic condition that causes your body to produce thick, sticky mucus that can clog the lungs and other organs. All U.S. hospitals now screen for cystic fibrosis in newborns. Finding the condition earlier makes it easier for families to manage the symptoms and avoid chronic coughs.
  • Bronchiectasis – Bronchiectasis is a medical condition where the airways in the lungs are damaged and wider than they should be. This allows a buildup of mucus in the lungs, making it more likely that they’ll get infected. The most common symptom is a chronic productive cough, but it can also cause paroxysmal coughing and make it hard to breathe.

When to see a doctor about a chronic cough

Anytime you’re worried about a cough or another symptom is the right time to talk to a doctor or clinician. But if your child has been experiencing a chronic cough for four weeks or longer, or you’ve had a cough for eight weeks or more, definitely make a primary care appointment.

Primary care doctors are experts in diagnosing and treating hundreds of conditions. And if more advanced care is needed, they can connect you with a specialist such as an allergist, cardiologist or pulmonologist.