Apnea can come and go and be temporary. This can occur with obstructive sleep apnea, for example.

Prolonged apnea means a person has stopped breathing. If the heart is still active, the condition is known as respiratory arrest. This is a life-threatening event that requires immediate medical attention and first aid.

Prolonged apnea with no heart activity in a person who is not responsive is called cardiac (or cardiopulmonary) arrest. In infants and children, the most common cause of cardiac arrest is respiratory arrest. In adults, the opposite usually occurs, cardiac arrest most often leads to respiratory arrest.

Breathing difficulty can occur for many reasons. The most common causes of apnea in infants and small children are different from the most common causes in adults.

Common causes of breathing difficulties in infants and young children include:

• Asthma
• Bronchiolitis (inflammation and narrowing of the smaller breathing structures in the lungs)
• Choking
• Encephalitis (brain inflammation and infection that affects vital brain functions)
• Gastroesophageal reflux (heartburn)
• Holding one's breath
• Meningitis (inflammation and infection of the tissue lining the brain and spinal cord)
• Pneumonia
• Premature birth
• Seizures

Common causes of breathing trouble (dyspnea) in adults include:

• Allergic reaction that causes tongue, throat, or other airway swelling
• Asthma or other lung diseases
• Cardiac arrest
• Choking
• Drug overdose, especially due to alcohol, narcotic painkillers, barbiturates, anesthetics, and other depressants
• Fluid in the lungs
• Heart attack
• Irregular heart beat
• Metabolic (body chemical, mineral, and acid-base) disorders
  
• Obstructive sleep apnea

Other causes of apnea include:

• Cardiac arrest
• Head injury or injury to the neck, mouth, and larynx (voice box)
• Near drowning
• Stroke and other brain and nervous system (neurological) disorders
• Injury to the chest wall, heart, or lungs 
  

Seek immediate medical attention or call your local emergency number (such as 911) if a person with any type of breathing problem:

• Becomes limp
• Has a seizure
• Is not alert (loses consciousness)
• Remains drowsy
• Turns blue

If a person has stopped breathing, call for emergency help and perform CPR (if you know how). When in a public place, look for an automated external defibrillator (AED) and follow the directions.

CPR or other emergency measures will be done in an emergency room or by an ambulance emergency medical technician (EMT) or paramedic.

Once the person is stable, the health care provider will do a physical exam, which includes listening to heart sounds and breath sounds.

Questions will be asked about the person's medical history and symptoms, including:

TIME PATTERN

• Has this ever happened before?
• How long did the event last?
• Has the person had repeated, brief episodes of apnea?
• Did the episode end with a sudden deep, snorting breath?
• Did the episode occur while awake or asleep?

RECENT HEALTH HISTORY

• Has the person had a recent accident or injury?
• Has the person been ill recently?
• Was there any breathing difficulty before breathing stopped?
• What other symptoms have you noticed?
• What medicines does the person take?
• Does the person use street or recreational drugs?

Diagnostic tests and treatments that may be done include:

• Airway support, including oxygen, breathing tube through the mouth (intubation), and breathing machine (ventilator)
• Blood and urine tests
• Chest tube
• Chest x-ray
• CT scan
• Defibrillation (electrical shock to the heart)
• ECG (electrocardiogram, or heart tracing)
• Fluids through a vein (intravenous or IV)
• Medicines to treat symptoms, including antidotes to reverse the effects of a poisoning or overdose

Respiration slowed or stopped; Not breathing; Respiratory arrest; Apnea

Easter JS. Pediatric resuscitation. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 158.

Haas NL, Kurz MC. Adult resuscitation. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 5.

Hartman ME, Cheifetz IM. Pediatric emergencies and resuscitation. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 81.

Updated by: Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.