Expiratory Grunting and Respiratory Distress in Infants Illustration

Expiratory Grunting and Respiratory Distress in Infants

by | Updated: Mar 15, 2024

Expiratory grunting in infants can be a worrying sign for parents and caregivers, as it often indicates that a baby is experiencing some form of respiratory distress.

This irregular breathing pattern can be caused by various factors, from infection to anatomical abnormalities.

Understanding what causes infant grunting and how to recognize it can help parents and caregivers take appropriate action to ensure their little ones get the care they need.

In this article, we’ll explore the different causes of infant grunting, as well as the signs to look for and ways to respond. So, whether you’re a new parent or a seasoned caregiver, keep reading to learn more about this important topic.

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What is Expiratory Grunting?

Expiratory grunting is an abnormal breathing pattern that occurs in infants due to increased resistance to airflow in the airways. It’s an indication of respiratory distress and should not be ignored or dismissed as a normal finding.


As previously mentioned, infant grunting can be caused by various factors, including infection, anatomical abnormalities, and even normal development.

One of the most common causes is a condition known as transient tachypnea of the newborn (TTN). This occurs when a baby’s lungs cannot clear fluid as quickly as they should after birth, leading to difficulty breathing and a characteristic grunting noise.

Another common cause of infant grunting is a lower respiratory tract infection, such as pneumonia or bronchiolitis. These conditions can cause inflammation and mucus buildup in the lungs, making it difficult for the infant to breathe.

In some cases, grunting may also be a sign of a more serious condition, such as a congenital diaphragmatic hernia.

This is a birth defect in which the diaphragm does not form properly, allowing organs from the abdomen to push into the thoracic cavity and restrict lung growth.

Recognizing the signs of infant grunting can be challenging, as the noise can be difficult to hear and may not always be present. However, some common signs to look for include:

  • Rapid breathing
  • Difficulty breathing
  • Flaring nostrils
  • Chest retractions (when the chest or neck moves in with each breath)
  • Cyanosis (a bluish discoloration of the skin, particularly around the lips or fingernails)

Other Causes

Some other conditions that may cause expiratory grunting include:

  • Meconium aspiration syndrome
  • Infant respiratory distress syndrome (IRDS)
  • Bronchopulmonary dysplasia

If you suspect your baby is grunting or experiencing difficulty breathing, it is important to seek medical attention immediately. The doctor can thoroughly examine and determine the cause of respiratory distress.

Infant expiratory grunting doctor stethoscope illustration


Treatment for grunting will depend on the underlying cause, but some examples include:

  • Nasal CPAP therapy
  • Antibiotics for infection
  • Exogenous surfactant in premature infants
  • Oxygen therapy for hypoxemia
  • Surgery for congenital diaphragmatic hernia

Expiratory grunting is also one factor determining an infant’s Silverman-Anderson Index.

This test is used to determine an infant’s level of respiratory distress by assessing their chest movement, intercostal retractions, xiphoid retractions, nasal flaring, and, of course, expiratory grunting.


What are the Most Common Signs of Respiratory Distress in Infants?

The most common signs of respiratory distress in infants can include:

  • Tachypnea
  • Grunting
  • Nasal flaring
  • Chest retractions
  • Cyanosis
  • Apnea
  • Tachycardia
  • Increased work of breathing

Please seek medical attention immediately if you suspect your baby is experiencing respiratory distress, including one or more of the symptoms above.

What is Bronchiolitis?

Bronchiolitis is a lower respiratory tract infection caused by a viral infection, most commonly by the respiratory syncytial virus (RSV). This infection affects the small airways (i.e., bronchioles) in the lungs, causing inflammation and mucus production.

This can result in dyspnea and an increased work of breathing. Bronchiolitis typically occurs in infants and young children, often during the fall and winter months.

What is Meconium Aspiration Syndrome?

Meconium aspiration syndrome is a condition that occurs when a newborn inhales a mixture of meconium and amniotic fluid during delivery. Meconium is a sticky substance that is present in the intestines of all fetuses. It is normally passed during the first few days after birth.

However, if the fetus is in distress, meconium can be passed into the amniotic fluid. If this occurs and the baby takes a breath in, meconium can get into the lungs and cause respiratory distress and severe breathing problems.

What is Infant Respiratory Distress Syndrome (IRDS)?

Infant Respiratory Distress Syndrome (IRDS) is a serious lung disorder that primarily affects premature infants. It is caused by a lack of surfactant, which is a substance that helps to keep the alveoli from collapsing.

Without enough surfactant, atelectasis occurs, making it difficult for the infant to take in enough oxygen. This can result in hypoxemia, labored breathing, and respiratory distress.

What is Bronchopulmonary Dysplasia?

Bronchopulmonary dysplasia (BPD) is a chronic lung disease that primarily affects premature infants who have required mechanical ventilation and oxygen therapy for a prolonged period of time.

It’s characterized by abnormal lung development and inflammation, resulting in respiratory distress, difficulty breathing, and increased risk of infections.

Final Thoughts

In summary, the most important thing to know about expiratory grunting in infants is that it’s an indication of respiratory distress.

Therefore, this abnormal breathing pattern should not be ignored or dismissed. This is especially true if accompanied by other signs and symptoms, such as rapid breathing, dyspnea, nasal flaring, retractions, or cyanosis.

Understanding the causes and recognizing the signs of grunting can help ensure that the infant receives the proper care and treatment. This can also help prevent complications and other potentially serious conditions.

This is why it’s important to stay informed and aware of the signs of grunting so that you can take the necessary steps to keep the infant healthy and happy.

John Landry, BS, RRT

Written by:

John Landry, BS, RRT

John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.


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