Oxygen Therapy: Types, Benefits, Risks and Home Safety
Updated: 6 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026 · How we review
Quick Answer: What is oxygen therapy?
Oxygen therapy is a treatment that delivers extra oxygen to the lungs through a nasal cannula or mask from a tank or machine when breathing alone does not supply enough. It is used for conditions such as COPD, pneumonia and heart failure, during surgery and in emergencies. Chest pain or severe breathlessness while on oxygen needs emergency care. [1]
What the research says
Long-term oxygen did not help people with COPD and only moderately low oxygen. In a trial of 738 patients at 42 centers, followed for 1 to 6 years, long-term oxygen did not delay death or first hospital stay (hazard ratio 0.94) and gave no lasting gain in quality of life, lung function or walking distance. (Long-Term Oxygen Treatment Trial Research Group, N Engl J Med, 2016) [3]
More oxygen than needed raised the risk of death in acutely ill adults. A meta-analysis of 25 randomized trials with 16,037 patients found that a liberal oxygen strategy increased in-hospital deaths by 21% (relative risk 1.21) compared with a conservative strategy; extra oxygen may become harmful once saturation is above about 94–96%. (Chu et al., Lancet, 2018) [4]
Routine oxygen did not help suspected heart attack patients whose oxygen levels were normal. Among 6,629 patients with oxygen saturation of 90% or higher, death within one year was 5.0% with oxygen and 5.1% with room air (hazard ratio 0.97). (Hofmann et al., N Engl J Med, 2017) [5]
Key takeaways
Oxygen therapy is a prescribed treatment for people who are not getting enough oxygen from normal breathing. [1]
Oxygen comes from one of three systems: a compressed gas cylinder, liquid oxygen or an oxygen concentrator. [1][2]
Used as directed, it can ease breathlessness, boost energy and improve sleep and quality of life. [1]
Too much oxygen is harmful, and oxygen makes fires burn faster, so dose and safety rules matter. [1][4]
Why does the body need supplemental oxygen?
The body needs supplemental oxygen when the lungs cannot move enough oxygen into the blood to keep organs working. [1]
When you breathe in, air travels down your airways to your lungs. Oxygen then passes from the lungs into the blood, which carries it to your organs and tissues as fuel. [1]
Lung problems can break this chain. The result is low blood oxygen, called hypoxemia. Over time, hypoxemia can damage organs and lead to organ failure, and a severe lack of oxygen can be life-threatening. [1]
Who needs oxygen therapy?
People who need oxygen therapy are those whose oxygen levels stay low because of a long-term condition, an infection, surgery or an emergency. [1]
A healthcare provider may prescribe it when your oxygen levels are consistently low. [1]
Situation | Examples |
Long-term lung conditions | COPD, asthma, cystic fibrosis, pulmonary fibrosis |
Heart conditions | |
Infections | Pneumonia, COVID-19, the flu |
Sleep-related breathing problems | Sleep apnea |
Other conditions | Cancer |
Hospital care | Emergencies and surgery |
High altitude | Mountain climbers and people living in or visiting high places |
Air holds less oxygen at high altitude, which can lead to altitude sickness. That is why climbers and people in high places sometimes need extra oxygen. [1]
How does oxygen therapy work?
Oxygen therapy works by sending extra oxygen from a tank or machine into your lungs through a nasal tube or a face mask. [1]
The thin nasal tube is called a nasal cannula. If you cannot breathe on your own, a healthcare provider gives oxygen through a tube placed in your windpipe (trachea). [1]
You can receive oxygen therapy at home, in a hospital or in another medical facility. [1]
What are the types of oxygen therapy systems?
The three types of oxygen therapy systems are compressed gas cylinders, liquid oxygen and oxygen concentrators. [1][2]
The right one depends on your needs. Some devices are large and stay in one place, while others are small and portable. [1]
System | What it is | Key features |
Compressed gas | 100% oxygen gas stored under pressure in a metal cylinder | A regulator controls the flow; a gauge shows when you need a new cylinder; an optional oxygen-conserving device stops the flow while you breathe out |
Liquid oxygen | Oxygen stored as a very cold liquid in a cylinder-shaped container | Smaller than compressed gas tanks; turns the liquid into gas for you to breathe |
Oxygen concentrator | A machine that pulls in room air and filters it | Removes nitrogen and concentrates the oxygen; needs no tank; does not run out of oxygen |
What are the benefits of oxygen therapy?
The benefits of oxygen therapy are less breathlessness, more energy, better sleep and a better quality of life for people who need it. [1]
Not getting enough oxygen can be fatal. Oxygen therapy helps your body get the oxygen it needs to keep your organs healthy and working. [1]
With oxygen therapy, you may:
Feel less out of breath during activities
Have more energy and be more physically active
Sleep better
Enjoy a better quality of life
What are the side effects of oxygen therapy?
The most common side effect of oxygen therapy is a dry nose, which can lead to nosebleeds. [1]
The serious risk is oxygen toxicity, also called oxygen poisoning. It happens when you take in more oxygen than your body needs or use oxygen when you do not need it, and it can slow your breathing and heart rate to dangerous levels. [1]
Type | What to watch for |
Common | Dry nasal passages, nosebleeds |
Oxygen toxicity (emergency) | Chest pain, difficulty breathing, dizziness, headaches, fatigue, muscle spasms, nausea, vision problems |
If you are on oxygen and notice signs of oxygen toxicity, call your local emergency number or go to the emergency room right away. [1]
How long will you need oxygen therapy?
How long you need oxygen therapy depends on your condition: some people need it for life, while others need it only until they recover. [1]
People with chronic conditions may use oxygen permanently. Others use it during a short-term illness or a flare-up of a long-term one. [1]
Your prescription also sets when you use it. Some people need oxygen all the time, while others need it only during sleep or exercise. Ask your healthcare provider what to expect. [1]
Is oxygen therapy safe at home?
Oxygen therapy is generally safe at home when you follow a few fire-safety rules. [1]
Oxygen is not flammable, but it makes a fire burn faster and stronger, and the fire can become explosive. [1]
Follow these safety rules while using oxygen: [1]
Stay at least 5 feet (about 1.5 meters) from open flames, including gas stoves, candles, fireplaces and firepits.
Never smoke near an oxygen tank or while wearing oxygen.
Stay at least 8 feet (about 2.4 meters) from heat-producing devices, such as heaters and electrical appliances.
Secure tanks upright to a stand or fixed object, and never roll a cylinder. A tank that falls or rolls may crack, and the pressure can make it explode.
Store tanks in a well-ventilated area so small leaks of oxygen spread into the air instead of building up.
Keep flammable products away from the tank, including aerosol sprays, cleaning products and oil (petroleum) products.
Choose cotton clothes and bedding over wool, nylon and synthetic fabrics, which can create sparks from static electricity.
Keep a fire extinguisher nearby, know how to use it and make sure your smoke alarms work.
When should you get emergency care while on oxygen therapy?
Emergency care is needed right away if you are on oxygen therapy and develop chest pain, confusion, extreme shortness of breath or other warning signs. [1]
Go to an emergency room or call your local emergency number if you have: [1]
Warning sign | Action |
Chest pain | Emergency care now |
Confusion or memory loss | Emergency care now |
Dizziness | Emergency care now |
Extreme shortness of breath | Emergency care now |
Nausea and vomiting | Emergency care now |
Severe headaches | Emergency care now |
For questions about your device, including how and when to use it, talk to your healthcare provider. [1]
Conclusion
Oxygen therapy gives your body the oxygen your lungs cannot supply on their own. It can help you breathe easier, feel more energetic and enjoy daily life. [1]
The key is using it exactly as prescribed. Oxygen helps when levels are low [1], but research shows extra oxygen brings no benefit, or added risk, when it is not needed. [4][5] Your care team will choose the system that fits your life, show you how to use it and set the dose that is right for you. [1]
Next step: If you or someone you care for uses oxygen, print the safety checklist above and keep it near the device. To learn more about the conditions behind low oxygen, read our guides on hypoxemia, the nasal cannula and what to do during an asthma attack. For patient handouts, see MedlinePlus: Oxygen Therapy and the American Lung Association's oxygen therapy guide.
FAQ
What is oxygen therapy used for?
Oxygen therapy is used to raise low blood oxygen caused by lung or heart conditions, infections, surgery or emergencies. Common examples include COPD, asthma, pneumonia, COVID-19, heart failure, cystic fibrosis and pulmonary fibrosis. [1]
Who needs oxygen therapy at home?
People with consistently low oxygen levels from a long-term condition may need oxygen therapy at home. A healthcare provider decides this and prescribes how much oxygen to use and when. [1]
What are the 3 types of oxygen therapy systems?
The 3 types of oxygen therapy systems are compressed gas cylinders, liquid oxygen and oxygen concentrators. Concentrators pull oxygen from room air, so they do not need a tank and do not run out. [1][2]
Can you get too much oxygen?
Too much oxygen can cause oxygen toxicity, which can slow breathing and heart rate to dangerous levels. Warning signs include chest pain, trouble breathing, dizziness, headaches, nausea and vision problems, and they need emergency care. [1]
Does oxygen therapy help if your oxygen levels are normal?
Oxygen therapy has not been shown to help people whose oxygen levels are normal. In a trial of 6,629 people with a suspected heart attack and normal oxygen levels, routine oxygen did not lower the one-year death rate. [5]
How long do people stay on oxygen therapy?
The length of oxygen therapy depends on the condition. People with chronic conditions may need oxygen for life, while others stop once a short-term illness or flare-up resolves. [1]
Can you smoke while using oxygen?
Smoking while using oxygen is never safe. Oxygen makes fire burn faster and stronger, so never smoke near an oxygen tank or while wearing oxygen. [1]
What are the side effects of oxygen therapy?
The most common side effect of oxygen therapy is a dry nose that can cause nosebleeds. The most serious risk is oxygen toxicity from using more oxygen than the body needs. [1]
Is oxygen therapy addictive?
No. Oxygen is not addictive, and your body does not become hooked on it. Whether you need it depends on your lung or heart condition.
How do you know your oxygen level?
A pulse oximeter clipped on your finger can estimate your oxygen level. Your provider will tell you the target range and what to do if you fall below it.
Related Reading
Oxygen Concentrator: How It Works, Types, Who Needs One, and Safety Tips explains how concentrators make oxygen from room air.
Oxygen Tank: Types, How to Use It Safely, and When to Call a Doctor explains compressed and liquid oxygen tanks and how to use them safely.
Hypoxemia: Causes, Symptoms, and Emergency Management explains low blood oxygen, its symptoms and when it is an emergency.
Pulse Oximetry: Normal Oxygen Levels, How It Works and What Affects Accuracy explains how a fingertip sensor measures blood oxygen levels.
References
Cleveland Clinic. Supplemental Oxygen Therapy: Types, Benefits & Risks. Cleveland Clinic. Last updated January 5, 2026. https://my.clevelandclinic.org/health/treatments/23194-oxygen-therapy
Hardavella G, Karampinis I, Frille A, et al. Oxygen devices and delivery systems. Breathe (Sheff). 2019;15(3):e108-e116. PMID 31777573. https://doi.org/10.1183/20734735.0204-2019
Long-Term Oxygen Treatment Trial Research Group; Albert RK, Au DH, Blackford AL, et al. A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation. N Engl J Med. 2016;375(17):1617-1627. PMID 27783918. https://doi.org/10.1056/NEJMoa1604344
Chu DK, Kim LH, Young PJ, et al. Mortality and morbidity in acutely ill adults treated with liberal versus conservative oxygen therapy (IOTA): a systematic review and meta-analysis. Lancet. 2018;391(10131):1693-1705. PMID 29726345. https://doi.org/10.1016/S0140-6736(18)30479-3
Hofmann R, James SK, Jernberg T, et al. Oxygen Therapy in Suspected Acute Myocardial Infarction. N Engl J Med. 2017;377(13):1240-1249. PMID 28844200. https://doi.org/10.1056/NEJMoa1706222
Medical disclaimer
This article is for general education and does not replace advice from your doctor. Oxygen is a prescribed treatment; never start, stop or change your oxygen flow without your healthcare provider's guidance. If you have chest pain, severe shortness of breath or confusion, call your local emergency number right away.
Comments