![Blood oxygen levels can also be measured using an instrument known as a pulse oximeter.](https://images.medicinenet.com/images/article/main_image/blood-oxygen-levels.jpg?resize=650px:*&output-quality=75)
Blood oxygen levels (arterial oxygen) indicate oxygen levels present in the blood that flows through the arteries.
- Blood oxygen levels can be checked by withdrawing blood from an artery in the wrist, elbow, or groin.
- You may feel a sharppainwhen the needle enters the artery.
- The blood is put in an ABG machine (bloodgasanalyzer) that provides blood oxygen level readings in the form of the partial pressure of oxygen (PaO2).
- In clinical studies, the blood oxygen level measurement feature on the Apple Watch has shown good accuracy when compared to a traditional pulse oximeter, which is a device commonly used to measure blood oxygen levels.
What are normal oxygen levels by age?
Pulseoximetrymeasures blood oxygen levels using a pulse oximeter, which is a small, mobile medical device. It is most commonly used when doctors want to quickly assess your blood oxygen levels. It is also used to monitor the response of your body to certain medications or supplemental oxygen.The procedure is very simple and requires only clipping the pulse oximeter in between any of the fingers for a few seconds. The reading appears on the pulse oximeter screen. Blood oxygen levels are indicated as SpO2, which is the percent saturation of oxygen in the blood.
- 95%-100%: Normal oxygen levels in a pulse oximeter usually range from 95%-100%. Note: Normal levels may vary if you have lung disorders. Your doctor can tell what levels are normal for you.
- Below 95%: People with SpO2 level fall below 95% such as 92% should see a healthcare provider as it may be a sign ofhypoxemia.
- Below 80-85%: The brain gets affected when the SpO2 level falls below 80-85%.
- Below 67%:Cyanosisdevelops when the SpO2 level drops below 67%.
Conditions | By Age | SpO2 |
---|---|---|
Normal | Adults & Children | 95% to 100% |
Normal | >70 years old | about 95% |
Brain is affected | Adults & Children | 80% to 85% |
Cyanosis | Adults & Children | Below 67% |
Pulse oximetry may be slightly less accurate than ABG but is easier to perform than ABG tests when results are needed quickly.
How are blood oxygen levels checked using the ABG test?
The blood is put in an ABG machine (blood gas analyzer) that provides your blood oxygen levels in the form of the partial pressure of oxygen (PaO2).
- Above 120 mmHg: Hyperoxemia is defined as blood oxygen levels above 120 mmHg. Hyperoxemia is mostly seen in hospitals when patients are exposed to high pressures of supplemental oxygen for prolonged periods (3 to more than 10 hours).
- 75-100 mmHg: Normal arterial oxygen pressure (PaO2) is approximately 75 to 100 millimeters of mercury (75-100 mmHg).
- Below 75 mmHg: When the levels drop below 75 mmHg, the condition is called hypoxemia.
- Below 60 mmHg: Levels below 60 mmHg are considered very low and indicate the need for supplemental oxygen. Supplemental oxygen is provided through an oxygen cylinder that is connected to the nose via a tube, with or without a mask.
Conditions | PaO2 Levels in mmHg |
---|---|
Hyperoxemia | > 120 |
正常动脉氧压力 | 75-100 |
Hypoxemia | < 75 |
Critical low (supplemental oxygen is needed) | < 60 |
![](https://images.medicinenet.com//images/slideshow/energy-boosting-foods-for-copd-s1-salad-and-sandwich.jpg)
SLIDESHOW
COPD Foods to Boost Your Health - COPD Diet TipsSee SlideshowWhat causes blood oxygen levels to become low?
Blood oxygen levels can get low due to any of the problems that include:
- Low air oxygen levels:Atmospheric oxygen becomes extremely low at high altitudes such as mountainous regions.
- 减少容量of the body to take in oxygen:
- This can be caused by lung conditions that include:
- Asthma
- Emphysema(damage of the air sacs in the lung)
- Bronchitis
- Pneumonia
- Pneumothorax(leaking of air in the space between the lung and chest wall)
- Acute respiratory distress syndrome(ARDS)
- Pulmonary edema(the lung swells due to build-up of fluid)
- Pulmonary fibrosis(scarring of thelungs)
- Interstitial lung disease(a large group of lung disorders that generally cause progressive scarring of the lungs)
- Viral infections such asCOVID-19
- This can be caused by lung conditions that include:
- Other conditions include:
- Anemia
- Sleep apnea(temporary cessation ofbreathingduringsleep)
- Smoking
- 减少容量of theheartto supply the oxygenated blood back to the lungs:The most common causes are congenital heart diseases (heart defects present by birth).
Health News
- Could Hair Relaxers Affect a Woman's Fertility?
- Lymph Node Removal During Breast Cancer Mastectomy: Is It Overdone?
- Opioid Addiction Treatment Rates in U.S. Have Flatlined, Study Finds
- Many American Teens Are in Mental Health Crisis: Report
- Why People Love Selfies: It's Not About Vanity
More Health News »
What are the signs and symptoms of low blood oxygen levels (hypoxemia)?
Hypoxemia can give rise to many signs and symptoms depending on its severity, which may include:
- Headache(mild to severe)
- Shortness of breath
- Dizziness
- Coughing
- Wheezing(breathing with a whistling or rattling sound in the chest)
- Confusion
- Rapid heartbeat
- Cyanosis (bluish color in the skin, fingernails, and lips)
Not having enough blood oxygen levels results in inadequate oxygen supply to the organs and tissues of the body. Severe hypoxemia can become dangerous. If left untreated for a long time, it can end up affecting the brain or heart.
How is hypoxemia treated?
Treating hypoxemia involves measures that increase the levels of oxygen in the blood, which is achieved by:
- Treating underlying conditions:Treating the cause of hypoxemia is the most important part of the therapy that gives long-lasting effects. Many times, medications are given through an inhaler that quickly enables you to breathe the medicine into your lungs.
- Oxygen therapy:You are given supplemental oxygen through an oxygen cylinder (which can be portable). The pressure of delivered oxygen can be controlled.
How can you prevent hypoxemia?
你可以maintain your normal blood oxygen levels after you recover from hypoxemia. Lifestyle changes that can help prevent hypoxemia include:
- Deep breathing exercises
- Mildexercisesuch aswalkingor as advised by your doctor
- Yoga
- 吃一个健康,均衡的diet
- Drink water adequately
- Quit smoking
Health SolutionsFrom Our Sponsors
Hafen BB, et al. Oxygen Saturation. In: StatPearls [Internet]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK525974/
Cooper JS, et al. Oxygen Toxicity. In: StatPearls [Internet]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430743/
Starr N, et al. Pulse oximetry in low-resource settings during the COVID-19 pandemic. The Lancet Global Health. 2020 Sep 1;8(9):e1121-2.
顶部是什么血Oxygen Levels? Related Articles
Anemia: Symptoms, Treatment and Causes
Anemia is the condition of having less than the normal number of red blood cells or less than the normal quantity of hemoglobin in the blood. The oxygen-carrying capacity of the blood is, therefore, decreased. There are several types of anemia such as iron deficiency anemia (the most common type), sickle cell anemia, vitamin B12 anemia, pernicious anemia, and aplastic anemia. Symptoms of anemia may include fatigue, malaise, hair loss, palpitations, menstruation, and medications. Treatment for anemia includes treating the underlying cause for the condition. Iron supplements, vitamin B12 injections, and certain medications may also be necessary.ARDS (Acute Respiratory Distress Syndrome)
Acute respiratory distress syndrome (ARDS) is a lung condition in which trauma to the lungs leads to inflammation of the lungs, accumulation of fluid in the alveolar air sacs, low blood oxygen, and respiratory distress. ARDS can be life-threatening. Signs and symptoms of are shortness of breath and low levels of oxygen in the blood, which can cause your organs to fail.
Causes of ARDS include:- Pneumonia
- Aspiration into the lungs
- Severe blow to the chest
- Sepsis
- Severe injury with shock
- Drug overdose
- Inflamed pancreas
- Other lung conditions and infections
- Burns
- Sepsis
- Near drowning
- Fractures
有遗传因素导致ARDS。Treatment for includes supplemental oxygen, and/or medication. According to some studies, survival rates for ARDS depend upon the cause associated with it, but can vary from 48% to 68%.
REFERENCES:
Harman, EM, MD. "Acute Respiratory Distress Syndrome Clinical Presentation." Medscape. Updated: Aug 11, 2016.
Harman, EM, MD. "Acute Respiratory Distress Syndrome." Medscape. Updated: Aug 11, 2016.
PubMed Health. "ARDS." Updated: Jun 11, 2014.
Reynolds, HN. et al. Acute respiratory distress syndrome: estimated incidence and mortality rate in a 5 million-person population base. Crit Care. 1998; 2(1): 29–34. Published online 1998 Mar 12. doi: 10.1186/cc121Asthma
Asthma is a condition in which hyperreactive airways constrict and result in symptoms like wheezing, coughing, and shortness of breath. Causes of asthma include genetics, environmental factors, personal history of allergies, and other factors. Asthma is diagnosed by a physician based on a patient's family history and results from lung function tests and other exams. Inhaled corticosteroids (ICS) and long-acting bronchodilators (LABAs) are used in the treatment of asthma. Generally, the prognosis for a patient with asthma is good. Exposure to allergens found on farms may protect against asthma symptoms.Blood Pressure Picture
The blood pressure is the pressure of the blood within the arteries. See a picture of Blood Pressure and learn more about the health topic.COPD vs. Asthma (Differences and Similarities)
COPD (chronic obstructive pulmonary disease) and asthma both have common symptoms like coughing, wheezing, shortness of breath, and a tight feeling in the chest. COPD is caused by tobacco smoking, while asthma is caused by your inherited genetic makeup and their interactions with the environment. Risk factors for asthma are obesity, exposure to cigarette smoke (even secondhand smoke), and personal history of hay fever. There is no cure for either disease, but symptoms can be managed with medication. A person with asthma has a better prognosis and life expectancy than someone with COPD.Hypoxia (Hypoxemia)
Hypoxia is a condition in which the normal concentration of oxygen in the blood is not enough for normal life functions. Symptoms of hypoxia and/or hypoxemia may be acute such as fast heart rate, rapid breathing, and shortness of breath; or severe symptoms include confusion, the inability to communicate, coma, and sometimes death. Treatment of hypoxia and/or hypoxemia is to provide supplemental oxygen to the body as soon as possible.
Low Blood Pressure
What is low blood pressure (hypotension)? Explore low blood pressure causes, symptoms, and signs. Discover what is considered low blood pressure.Safe, Normal, Low Blood Oxygen Levels: Pulse Oximeter Chart
What should your oxygen saturation be? What are normal and safe oxygen levels? How does a finger pulse oximeter work? Learn about blood oxygen levels, symptoms of low oxygen (hypoxemia), and ways to keep your blood oxygen levels in the normal range, with charts.Oximetry
Oximetry is a procedure used to measure the concentration of oxygen in the blood. Oximetry is used in the evaluation of various medical conditions that affect the function of the heart and lungs. Pulse oximeters are the most common oximeter used because they respond only to pulsations. Oximetry can also be done on blood within the heart, or on whole blood that has been removed from the body. Similar technology to oximetry is currently used to measure carbon dioxide levels at the skin.Pneumonia
Pneumonia is inflammation of the lungs caused by fungi, bacteria, or viruses. Symptoms and signs include cough, fever, shortness of breath, and chills. Antibiotics treat pneumonia, and the choice of the antibiotic depends upon the cause of the infection.Collapsed Lung (Pneumothorax)
A pneumothorax is air in the chest outside the lung that causes the lung to collapse (collapsed lung). There are two types of pneumothorax, spontaneous or primary pneumothorax and secondary pneumothorax. Symptoms include sudden chest pain, shortness of breath, rapid heart rate, rapid breathing, cough, and fatigue.What Are the Benefits of Pulse Oximetry?
Pulse oximetry is a quick, noninvasive test that measures the oxygen level (oxygen saturation) in the blood. It is an easy, painless method to measure how well oxygen is carried to parts of the body furthest from the heart, such as the arms and legs.What are the Three Major Causes of Pneumonia?
Pneumonia is a lung infection that affects many people. Learn the signs of pneumonia, what causes it, how doctors diagnose it, and what you can do to treat it.