Apparent Life-Threatening Event


Uh-Pare-Ent Life Thre-ten-ing E-vent



An apparent life-threatening event (ALTE) is a set of symptoms in an infant that cause the caregiver to believe the child may be dying or has died. It may include disturbed breathing, change in color, choking or gagging. Cardiopulmonary resuscitation (CPR) may be needed at the time of the event.

Infant Airway and Lungs

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The cause of ALTE is not always clear. Some likely causes of ALTE may include:

  • Digestive problems, such as gastroesophageal reflux disease
  • Neurological problems, such as a seizure disorder or problems with the breathing center in the brain
  • Respiratory problems, such as lung infection or something blocking the airway
  • Infections
  • Heart problems, such as an abnormal heartbeat
  • Problems with the endocrine system, which includes the glands and hormones
  • Metabolic problems, such as hypoglycemia
  • Child abuse

Risk Factors

Risk Factors

Boys and babies younger than 1 year of age are at higher risk of ALTE. Other factors that may increase an infant’s risk of ALTE include:



Symptoms may include:

  • Breathing that stops
  • Changes in skin color—blue, red, or pale
  • Change in muscle tone—floppy or tense
  • Choking
  • Gagging



You will be asked about your baby’s symptoms and medical history, including what you noticed in the time leading up to the ALTE. A physical and neurological exam will be done. Your child’s condition may need to be observed short term in the hospital and followed closely long term after discharge.

To look for potential causes of ALTE the doctor may order:

  • Blood and urine tests may be done to look for infections or other problems in the body’s fluids.
  • X-rays and ultrasounds may also be done to take images of your baby’s bodily structures.

Other tests may include:



Talk with your doctor about the best treatment plan for your baby. Options include life-saving treatment if needed and treating the underlying cause of the ALTE. If the cause is unknown, treatment involves monitoring the child for symptoms.

Life-saving Treatment

CPR is a life-saving treatment that can be delivered by non-medical and medical people. It may restore breathing and blood circulation or help provide oxygen to the body until medical help arrives.

Consider taking a class in infant CPR so you are prepared.

Treating the Underlying Cause

If a cause is found, then the underlying condition will be treated.


In half of the babies who have an ALTE, the cause is not known. Home monitoring may be needed if advised by your baby’s doctor. A monitor can record your baby’s heart and breathing activity. An alert will sound if your baby is having another event. It may also sound for no reason (false positive)



There is no known way to prevent an ALTE.


Family Doctor—American Academy of Family Physicians

Healthy Children—American Academy of Pediatricians


Canadian Paediatric Society

Health Canada


ALTE—Apparent life-threatening event. Auckland District Health Board website. Available at:
Updated April 2012. Accessed October 30, 2014.

Apparent life-threatening event. EBSCO DynaMed website. Available at:
Updated February 19, 2013. Accessed November 1, 2013.

Apparent life threatening event ALTE. The Royal Children’s Hospital Melbourne website. Available at:
Accessed October 30, 2014.

Clinical practice guideline: apparent life threatening event (ALTE). Prince Margaret Hospital website. Available at:
Updated January 2009. Accessed October 30, 2014.

Hall K, Zalman B. Evaluation and management of apparent life-threatening events in children. Am Fam Physician. 2005 June 15;71(12):2301-2308.

7/28/2014 DynaMed’s Systematic Literature Surveillance
Sarohia M, Platt S. Apparent life-threatening events in children: practical evaluation and management. 2014 Apr;11(4):1-14.

Last reviewed December 2014 by Michael Woods, MD
Last Updated: 12/20/2014

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