Several factors are needed to continuously supply the cells and tissues in your body with oxygen:
- There must be enough oxygen in the air you are breathing
- Your lungs must be able to inhale the oxygen-containing air — and exhale carbon dioxide
- Your bloodstream must be able to circulate blood to your lungs, take up the oxygen and carry it throughout your body
A problem with any of these factors — for example, high altitude, asthma or heart disease — might result in hypoxemia, particularly under more extreme conditions, such as exercise or illness. When your blood oxygen falls below a certain level, you might experience shortness of breath, headache, and confusion or restlessness.
Common causes of hypoxemia include:
- Anemia
- ARDS [Acute respiratory distress syndrome]
- Asthma
- Congenital heart defects in children
- Congenital heart disease in adults
- COPD [chronic obstructive pulmonary disease] worsening of symptoms
- Emphysema
- Interstitial lung disease
- Medications, such as certain narcotics and anesthetics, that depress breathing
- Pneumonia
- Pneumothorax [collapsed lung]
- Pulmonary edema [excess fluid in the lungs]
- Pulmonary embolism [blood clot in an artery in the lung]
- Pulmonary fibrosis [scarred and damaged lungs]
- Sleep apnea
Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.
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Dec. 01, 2018
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- Wilkinson JM [expert opinion]. Mayo Clinic, Rochester, Minn. Nov. 28, 2015.
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- Broaddus VC, et al., eds. Acute hypoxemic respiratory failure and ARDS. In: Murray and Nadel's Textbook of Respiratory Medicine. 6th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. //www.clinicalkey.com. Accessed Nov. 18, 2015.
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Signs of Respiratory Distress in Children
Learning the signs of respiratory distress
Children having difficulty breathing often show signs that they are having to work hard to breathe or are not getting enough oxygen, indicating respiratory distress. Below is a list of some of the signs that may indicate that your child is not getting enough oxygen. It is important to learn the signs of respiratory distress to know how to respond appropriately:
Breathing rate. An increase in the number of breaths per minute may indicate that a person is having trouble breathing or not getting enough oxygen.
Increased heart rate. Low oxygen levels may cause an increase in heart rate.
Color changes. A bluish color seen around the mouth, on the inside of the lips, or on the fingernails may happen when a person is not getting as much oxygen as needed. The color of the skin may also appear pale or gray.
Grunting. A grunting sound can be heard each time the person exhales. This grunting is the body's way of trying to keep air in the lungs so they will stay open.
Nose flaring. The openings of the nose spreading open while breathing may indicate that a person is having to work harder to breathe.
Retractions. The chest appears to sink in just below the neck and/or under the breastbone with each breath--one way of trying to bring more air into the lungs.
Sweating. There may be increased sweat on the head, but the skin does not feel warm to the touch. More often, the skin may feel cool or clammy. This may happen when the breathing rate is very fast.
Wheezing. A tight, whistling or musical sound heard with each breath can indicate that the air passages may be smaller, making it more difficult to breathe.
Stridor. An inspiratory sound heard in the upper airway.
Accessory muscle use. The muscles of the neck appear to be moving when your child breathes in. This can also be seen under the rib cage or even the muscles between the ribs.
Changes in alertness. Low oxygen levels may cause your child to act very tired and may indicate respiratory fatigue.
Body positions. Low oxygen and difficulty breathing may force your child to thrust his or head backwards with the nose up in the air [especially if lying down]. Or, your child may lean forward while sitting. A child automatically uses these positions as a last attempt to improve breathing.
The signs of respiratory distress may resemble other problems or medical conditions. Always consult your child's healthcare provider for a diagnosis, but if your child is having difficulty breathing, call 911 or go to the closest emergency room.