Parainfluenza (Human Parainfluenza Viruses)

Parainfluenza refers to a group of viruses — human parainfluenza viruses (HPIVs) — that cause common respiratory infections. This includes illnesses like colds, croup, bronchiolitis, bronchitis and pneumonia. They’re more likely to cause severe illness in children younger than 5, adults older than 65, and people with weakened immune systems.


What is parainfluenza?

Parainfluenza is a broad term that healthcare providers use to describe human parainfluenza viruses (HPIVs) — a group of infectious organisms (pathogens). Parainfluenza viruses cause many types of lower and upper respiratory illnesses. Respiratory illnesses cause mild to serious symptoms, like sore throat, cough and shortness of breath.

HPIV infections can affect anyone. They’re common in infants and children. It’s possible to get infected with HPIVs many times in your life, even if you’ve had one when you were younger. You’re less likely to get severe illness after your first infection (usually in childhood).

HPIV illnesses have a seasonal pattern. They’re more common in the fall, winter and spring.

Types of parainfluenza viruses

There are four commonly recognized types of parainfluenza viruses:

  • HPIV-1 and HPIV-2. HPIV-1 and HPIV-2 are more likely to cause colds and croup.
  • HPIV-3. HPIV-3 is more likely to infect your airways and lungs, causing bronchiolitis, bronchitis or pneumonia.
  • HPIV-4. We don’t know as much about HPIV-4, but experts think it causes illnesses similar to HPIV-3.

Is parainfluenza the same as the flu, RSV or COVID-19?

Parainfluenza, the flu, RSV and COVID-19 are caused by different viruses, but they can all have similar symptoms. All of these viral infections can lead to serious conditions, like pneumonia. The only way to know which one you have is for a healthcare provider to test you.

The name “parainfluenza” sounds the same as “influenza” (the virus that causes the flu) because experts used to think they were a similar type of virus. But they’re different illnesses.

How common is parainfluenza?

Parainfluenza infections are very common, especially in infants and children. More than 75% of children older than 5 and 90% of adults have evidence of a previous infection with an HPIV. Researchers find this evidence in antibodies in their blood, which shows that their immune systems fought off an infection in the past.

How serious is parainfluenza?

Parainfluenza is usually not serious in healthy adults. If you have other health issues, like chronic lung disease or a compromised immune system, a parainfluenza infection can be more severe and slow to recover from.

You’re more likely to experience severe illness from HPIVs if you:

  • Are younger than 5.
  • Are older than 65.
  • Have a compromised immune system, particularly if you’ve received an organ donation.
  • Have a chronic lung condition such as asthma, COPD or interstitial lung disease.


Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Symptoms and Causes

What are the symptoms of human parainfluenza viruses?

Symptoms of the HPIVs are usually mild in adults but can be more severe in children or those with a compromised immune system. They include:

  • Fever.
  • Cough. This can be a mild cough, a barky cough (croup) or a persistent cough with mucus (bronchitis).
  • Runny or stuffy nose.
  • Sore throat.
  • A high-pitched sound when you breathe (wheezing or stridor).
  • Hoarseness.
  • Sneezing.

How do you get parainfluenza virus?

You get HPIVs from direct or indirect contact with someone else who’s infected. Common ways to get a parainfluenza infection include:

  • From someone nearby coughing or sneezing. Very small (microscopic) droplets containing HPIV can get into your nose or mouth directly through the air. They can also get on your hands, then get into your nose or mouth when you touch your face.
  • Touching a surface that’s contaminated with parainfluenza virus, then touching your face, mouth, nose or eyes. This includes things like doorknobs, computers and phones.
  • Touching the hands or face of someone who is sick with parainfluenza virus, then touching your face, mouth, nose or eyes.
  • Kids can get it from other kids or from touching things like desks, toys and playground equipment.

Is parainfluenza very contagious?

Parainfluenza spreads easily from person to person. It’s particularly contagious among young children, who often put toys and their hands in their mouths, and who don’t understand hygiene the way adults do.


Diagnosis and Tests

How is parainfluenza virus diagnosed?

It’s usually not necessary for your provider to test for parainfluenza viruses. If they do, they’ll use a long stick with a soft tip (swab) to take a sample of mucus from your nose or throat. They’ll send it to a lab to test for HPIVs and other viruses or bacteria (infectious diseases).

Usually, providers diagnose illnesses you get from HPIVs by asking about your symptoms and examining you. During your exam, they might:

  • Listen to your heart and lungs.
  • Look in your nose and mouth.
  • Take your blood pressure with a cuff around your arm.
  • Test how much oxygen is in your blood with a clip on your finger (pulse oximeter, or pulse ox).

Management and Treatment

How do I manage symptoms of parainfluenza virus?

Many people can manage the symptoms of mild HPIV infections at home. Adults can usually take over-the-counter (OTC) medications, but ask your child’s healthcare provider before giving them any medications. Children younger than 16 shouldn’t take aspirin.

Some things you can do to treat your symptoms at home include:

  • Getting plenty of rest.
  • Drinking fluids like water or broth to stay hydrated.
  • Running a humidifier in your room or your child’s room to keep the air moist. This can relieve a sore throat, stuffy nose and cough.
  • Using acetaminophen (Tylenol®) or NSAIDs (Motrin®, Advil®, Aleve®) can help lower fever and relieve aches and pains.
  • Using decongestants, cough suppressants, expectorants or throat lozenges might also help, depending on which symptoms are bothering you.



How can I prevent parainfluenza?

There’s no vaccine for parainfluenza viruses. You can reduce your risk of getting sick with everyday habits, including:

  • Washing your hands often with soap and water. If you aren’t able to use soap and water, use an alcohol-based hand sanitizer.
  • Covering your nose and mouth when you sneeze or cough. Coughing or sneezing into your elbow or a tissue rather than your bare hand.
  • Avoiding being around other people when you or they are sick with colds or other infectious diseases.
  • Wearing a mask if you’re sick and can’t avoid being around others.
  • Avoiding touching your face, eyes, nose and mouth.
  • Not sharing food or eating utensils (forks, spoons and cups) with others.
  • Teaching kids how to wash their hands properly and other hygiene habits early.

Outlook / Prognosis

What can I expect if I have an infection with parainfluenza virus?

Most people get infected with an HPIV before they’re 5 years old. Older children and adults usually get milder symptoms with additional infections. Most people are able to manage their symptoms at home, but keep an eye out for serious symptoms. Young children, people with chronic lung disease and people with weakened immune systems are most at risk for getting severely ill.

How long does parainfluenza last?

Depending on what kind of HPIV infection you have, you can be sick for a few days to a week. Some symptoms can linger for two weeks or longer.

Complications of parainfluenza virus

Children younger than 5, adults older than 65 and people with compromised immune systems are more likely to have severe illness from HPIVs. The most common complications are pneumonia and severe forms of croup. Both can make breathing difficult and might require hospitalization.

HPIV infections are one of the most common causes of hospitalization in children with respiratory illness.

Living With

When should I see my healthcare provider?

See a healthcare provider if you or your child has symptoms of serious illness or croup, including:

  • A barky cough.
  • Noisy breathing.
  • Trouble breathing.

When should I go to ER?

Go to the ER or seek immediate medical attention if you or your child has symptoms of severe illness, including:

  • High fever (over 103 degrees Fahrenheit/40 degrees Celsius).
  • Difficulty breathing.
  • Not peeing or peeing very little.
  • Pain in your chest or stomach (abdomen) that doesn’t go away.
  • Persistent dizziness.
  • Severe muscle pain or weakness.
  • Bluish skin, lips or nails (cyanosis, which can be a sign of low oxygen levels in your blood).
  • Seizures.

What questions should I ask my doctor?

It might be helpful to ask your healthcare provider:

  • How do I treat my symptoms at home?
  • Which over-the-counter medications can I use?
  • Which medications can I give to my child?
  • Which severe symptoms should I look out for?
  • When should I go to the ER?
  • When should I follow up with you?
  • How long might it take to feel better?

A note from Cleveland Clinic

Parainfluenza viruses (HPIVs) cause many common illnesses, from “the sniffles” to croup. Most adults might barely notice they have one. On the other hand, some people can get very sick from HPIVs. If you’re older than 65 or have a weakened immune system, or if you have a child younger than 5, it’s important to keep a close eye out for serious illness. Don’t hesitate to contact a healthcare provider or go to the nearest ER if you or your child is having severe symptoms.

Medically Reviewed

Last reviewed on 12/12/2022.

Learn more about our editorial process.

Appointments 216.444.6503