Version July 2025
Please read the Disclaimer at the end of this page.
What is oxygen? —
Oxygen (O2) is a gas in the air we breathe. The body needs oxygen to survive. You take oxygen into your lungs when you breathe in air. The oxygen passes through the tiny air sacs in your lungs into your blood. From there, the oxygen is taken to your organs.
What is oxygen therapy? —
This is getting extra oxygen. Your doctor might order extra oxygen if you have a disease where you do not get enough oxygen into your blood. Extra oxygen might help ease symptoms like shortness of breath, tiredness, or feeling dizzy.
Some people need extra oxygen for:
●Short-term problems like an infection, asthma flare-up, or other lung problems
●Long-term problems like chronic obstructive pulmonary disease ("COPD"), cystic fibrosis, or emphysema
●Heart problems like a heart attack or heart failure
Oxygen can be:
●Compressed – Oxygen is stored in metal tanks under high pressure. The tanks come in different sizes. Some are small enough to carry around with you.
●Liquid – Liquid oxygen is very cold. It turns into a gas when you breathe. It takes up less room than other types of oxygen, but costs more.
●Concentrated – This uses oxygen already in the air. An electric machine filters out other gases and keeps just the oxygen. There are also portable oxygen concentrators that use a battery instead of electricity.
What happens before I start using oxygen? —
Your doctor will place a small device called a "pulse oximeter" on 1 of your fingers. This measures the amount of oxygen in your blood. Sometimes, your doctor might order an arterial blood gas ("ABG") test. This is a blood test that shows how much oxygen is in your blood.
These help your doctor know how much extra oxygen you need and when you need to use it.
How do I use oxygen therapy? —
Your doctor will order how much oxygen you need, similar to how they prescribe medicines.
Oxygen therapy is measured in 2 different ways. Some people call this the "flow rate" or "oxygen setting." Your doctor might order an amount of flow, like 2 or 3 liters per minute. Or they might order a percent of oxygen, like 40% or 50%. Sometimes, your doctor will order your oxygen using both numbers.
The oxygen can be given in different ways. You might need to use a:
●Nasal cannula – This delivers oxygen through 2 small tubes you place in your nostrils (figure 1).
●Mask – This goes over your nose and mouth.
How do I care for myself at home? —
Ask the doctor or nurse what you should do when you go home. Make sure you understand exactly what you need to do to care for yourself. Ask questions if there is anything you do not understand.
●Before you go home, your doctor or nurse will talk with you about when to use oxygen and how much. Some people need to use oxygen all the time. Others use it only when sleeping or when active. Follow all instructions carefully.
●Make sure you have extra oxygen tanks, tubing, nasal cannula, and face masks in case of an emergency. Know how to clean all the parts and when to replace them. Make sure the tubing is not pinched or blocked.
●Each day, check your skin under your oxygen tubing or mask. Talk to the doctor or nurse if you have:
•Redness or irritation that does not go away after 15 minutes
•A sore on your skin
●When you need to use oxygen at home, an oxygen supplier will set up the equipment in your house. Make sure you know:
•The name and phone number of the supplier
•How long it takes to get oxygen delivered. This helps you know when to order more so you don't run out.
•How to connect and use all the parts
•How often to change or clean your equipment. Learn if there are filters that need to be replaced or cleaned, and how often.
What else should I know? —
Some important safety tips to remember when using oxygen:
●Tell your electric company if you use an oxygen concentrator. You might need to have a back-up power source if your electricity goes off. Also, tell your local fire department and gas companies you use oxygen at home.
●Never smoke or light flames around the oxygen device. Do not let others smoke around you. This is very important. You could be seriously burned if there is ever a flame or lit cigarette around oxygen.
●Never use the oxygen device near a gas heater or stove.
●Do not use lotions and creams with petroleum in them.
●Store the oxygen tanks upright. Make sure they cannot fall over.
●Turn off the oxygen supply when not in use.
●Have working smoke detectors in your home.
●Take extra care when moving around. It is easy to trip over the oxygen tubing.
●You might need to make special arrangements if you travel by plane. Most airlines will only accept a portable oxygen concentrator. Tell your doctor about any plans for air travel.
When should I call the doctor? —
Call for advice if:
●You have symptoms of not enough oxygen – These might include chest pain, trouble breathing, loss of appetite, trouble sleeping, dizziness, feeling drowsy, or blue or gray skin around your eyes, lips, or fingernails.
●You are having so much trouble breathing you can only say 1 or 2 words at a time.
●You need to sit upright to breathe, or cannot lie down.
●You have trouble breathing when talking or sitting still.
●You have signs of infection. These include a fever of 100.4°F (38°C) or higher, chills, cough, or more mucus or change in mucus color.
●Your nose feels very dry inside, or you get a bloody nose.
●You do not remember what your oxygen settings should be.
●You cannot get the oxygen that is ordered for you.
Patient education: Shortness of breath (The Basics)
Patient education: Chronic obstructive pulmonary disease (COPD) (The Basics)
Patient education: Cystic fibrosis (The Basics)
Patient education: Pulmonary hypertension (The Basics)
Patient education: How to use a pulse oximeter (The Basics)
Patient education: Arterial blood gas test (The Basics)
Patient education: Chronic obstructive pulmonary disease (COPD) (Beyond the Basics)
Patient education: Supplemental oxygen on commercial airlines (Beyond the Basics)
