A cough is a reflex that your body uses to clear your airways and to protect your lungs from foreign materials and infection.

You may cough in response to many different irritants. Some common examples include:

  • pollen
  • smoke
  • infections

While occasional coughing is normal, sometimes it can be caused by a more serious condition that needs medical attention. That’s why it’s important to know when to see a doctor for a cough.

There are different classifications of coughs. These are based on the length of time the cough has been present.

  • Acute cough. Acute coughs last less than 3 weeks. In some cases, such as after a respiratory infection, a cough can linger between 3 and 8 weeks. This is called subacute cough.
  • Chronic cough. A cough is considered chronic when it lasts longer than 8 weeks.

Acute coughs can be caused by:

  • environmental irritants such as smoke, dust, or fumes
  • allergens like pollen, pet dander, or mold
  • upper respiratory tract infections, such as the common cold, the flu, or a sinus infection
  • lower respiratory infections like bronchitis or pneumonia
  • exacerbations of a chronic condition like asthma
  • more serious conditions, such as pulmonary embolism

Coughs can also be classified as productive or nonproductive.

  • Productive cough. Also called a wet cough, it brings up mucus or phlegm.
  • Nonproductive cough. Also called a dry cough, it doesn’t produce any mucus.

A cough is a common symptom of COVID-19, the illness caused by the new coronavirus, SARS-CoV-2.

The incubation period for COVID-19 can be between 2 to 14 days with an average of 4 to 5 days, according to the Centers for Disease Control and Prevention (CDC).

A cough that’s associated with COVID-19 is usually dry. However, the CDC notes that in some cases it can be wet.

If you have a mild case of COVID-19, you may choose to use cough medications or other home remedies to help ease your cough.

Along with a cough, other possible symptoms of COVID-19 include:

When to get emergency care for COVID-19

Some people may develop severe disease due to COVID-19. This typically happens 5 to 8 days after symptoms begin. Warning signs of serious COVID-19 illness for which you should seek immediate medical attention include:

  • difficulty breathing
  • pain or pressure in your chest that’s persistent
  • lips or face appearing blue in color
  • mental confusion
  • trouble staying awake or difficulty waking

An acute cough that’s caused by an irritant, allergens, or an infection will usually clear up within a few weeks.

But it’s a good idea to follow up with your doctor if it lasts longer than 3 weeks or occurs along with any of the following symptoms:

Seek emergency care for any cough that’s accompanied by:

If you have a mild cough, there are some things that you can do at home to help ease your symptoms. Some remedies include the following:

  • Over-the-counter (OTC) cough medications. If you have a wet cough, an OTC expectorant like Mucinex may help loosen up mucus from your lungs. Another option is an antitussive medicine like Robitussin which suppresses the cough reflex. Avoid giving these medications to children under 6 years of age.
  • Cough drops or throat lozenges. Sucking on a cough drop or a throat lozenge can help ease a cough or irritated throat. However, don’t give these to young children, as they can be a choking hazard.
  • Warm drinks. Teas or broths can thin mucus and reduce irritation. Warm water or tea with lemon and honey may also help. Honey shouldn’t be given to children under 1 year old due to the risk of infant botulism.
  • Extra moisture. Adding additional humidity to the air may help soothe a throat that’s become irritated from coughing. Try using a humidifier or stand in a warm, steamy shower.
  • Avoid environmental irritants. Try to stay away from things that could lead to further irritation. Examples include cigarette smoke, dust, and chemical fumes.

These home remedies should only be used for mild coughs. If you have a cough that’s persistent or happens with other concerning symptoms, seek medical attention.

If you do seek medical care for your cough, your doctor will often treat it by addressing the underlying cause. Some examples of treatment include:

Some medications, such as benzonatate, may also be used to reduce the coughing reflex.

Coughs are common and can be either acute or chronic. Additionally, some coughs may produce mucus while others may not.

A wide variety of factors can cause a cough. Some examples include environmental irritants, respiratory infections, or chronic conditions like asthma or COPD.

A cough is also a common symptom of COVID-19.

At-home care can often ease a cough. However, sometimes a cough needs to be evaluated by a doctor.

Call your doctor if your cough lasts longer than 3 weeks or if it’s accompanied by symptoms like:

  • fever
  • discolored mucus
  • shortness of breath

Some symptoms could be signs of a medical emergency. Seek immediate attention for a cough that happens alongside one or more of following symptoms:

  • trouble breathing
  • high fever
  • coughing up blood