Oxygen Therapy Explained: How It Works and When It Is Used
Oxygen is essential for life. Every cell in the body depends on a continuous supply of oxygen to produce the energy needed for normal function. While breathing is something most people rarely think about, certain respiratory conditions can make it difficult for the lungs to deliver enough oxygen to the bloodstream.
When this happens, oxygen therapy may become an important part of treatment. For people living with chronic respiratory diseases, supplemental oxygen can help maintain adequate oxygen levels and support daily life at home.
Understanding how oxygen therapy works, why it is prescribed, and the conditions associated with low blood oxygen levels can help patients and caregivers better navigate long-term respiratory care.
Why is oxygen important for the body?
Oxygen is a naturally occurring gas that makes up approximately 21% of the Earth's atmosphere. Every breath delivers oxygen into the lungs, where it passes into the bloodstream and is transported throughout the body.
Breathing is controlled automatically by the brain. Signals are sent to muscles in the chest and diaphragm, allowing the lungs to expand and contract.
When the diaphragm moves downward and the chest expands, air flows into the lungs. When these muscles relax, air is expelled. This continuous process supplies oxygen to tissues and removes carbon dioxide produced by the body's cells.
What is oxygen therapy?
Oxygen therapy is a medical treatment that increases the amount of oxygen available for breathing when the lungs cannot maintain adequate oxygen levels on their own.
The treatment involves supplying medical oxygen through specialised equipment prescribed by healthcare professionals. The goal is to improve oxygen delivery to the body when respiratory conditions reduce the lungs' ability to oxygenate the blood effectively.
Oxygen therapy does not replace normal breathing. Instead, it supplements the oxygen available to the patient when clinically required.
What is chronic respiratory failure?
Chronic respiratory failure occurs when the respiratory system is no longer able to maintain sufficient oxygen levels in the blood and, in some cases, remove carbon dioxide effectively.
As oxygen levels fall, the body may struggle to meet its normal metabolic needs. This condition develops gradually in many chronic respiratory diseases and often requires ongoing medical management.
Healthcare professionals may evaluate oxygen levels using several methods, including pulse oximetry and blood gas testing.
A pulse oximeter is a non-invasive device typically placed on a fingertip or earlobe to estimate oxygen saturation levels.
What are the symptoms of chronic respiratory failure?
Symptoms can vary depending on the underlying condition and severity of oxygen deficiency.
Common signs may include:
- Shortness of breath (dyspnea)
- Rapid or shallow breathing
- Reduced exercise tolerance
- Fatigue during everyday activities
When oxygen levels remain low for extended periods, additional complications may develop. These can include fluid retention and swelling in the lower limbs, which may be associated with changes in heart function.
What conditions can lead to chronic respiratory failure?
Several diseases can impair the lungs' ability to exchange oxygen and carbon dioxide effectively.
Common causes include:
- Chronic Obstructive Pulmonary Disease (COPD)
- Neuromuscular disorders such as Duchenne muscular dystrophy
- Amyotrophic lateral sclerosis (ALS)
- Obesity hypoventilation syndrome
- Other chronic respiratory diseases affecting lung function
The specific treatment plan depends on the underlying diagnosis, disease severity and individual clinical needs.
Understanding COPD and its relationship to oxygen therapy
COPD is one of the most common causes of chronic respiratory failure.
COPD is a group of chronic lung conditions that cause airflow limitation and make breathing more difficult over time. Chronic bronchitis and emphysema are among the most common forms of COPD.
The disease can affect both the airways and the air sacs within the lungs, reducing the body's ability to absorb oxygen efficiently.
Common symptoms may include:
- Persistent cough
- Increased mucus production
- Breathlessness during activity
- Reduced exercise capacity
Although COPD cannot currently be cured, it can often be managed through a combination of medical treatment, lifestyle measures and supportive therapies prescribed by healthcare professionals.
Learn more about COPD and respiratory health
How is chronic respiratory failure diagnosed?
Diagnosis is typically performed by a respiratory specialist or other qualified healthcare professional.
Assessment may include:
Spirometry
Spirometry measures how much air a person can inhale and exhale and helps evaluate lung function.
Blood gas analysis
Blood gas testing measures oxygen and carbon dioxide levels in the blood and helps determine the severity of respiratory impairment.
Pulse oximetry
Pulse oximetry provides a non-invasive estimate of oxygen saturation and is commonly used during assessment and ongoing monitoring.
Imaging studies
Chest X-rays or other imaging investigations may be used when clinically appropriate to evaluate lung structure and identify underlying causes.
Following diagnosis, healthcare professionals develop a personalised treatment plan based on the patient's condition and clinical requirements.
What treatments may be used alongside oxygen therapy?
Management of chronic respiratory diseases often involves multiple approaches working together.
Depending on the condition, treatment plans may include:
- Smoking cessation support
- Respiratory medications
- Pulmonary rehabilitation programmes
- Airway clearance techniques
- Physical activity programmes prescribed by healthcare professionals
- Non-invasive ventilation (NIV) in selected patients
- Long-term oxygen therapy when clinically indicated
The combination of treatments varies from person to person and should always follow medical guidance.
What is long-term oxygen therapy (LTOT)?
Long-term oxygen therapy (LTOT) is a form of oxygen therapy prescribed for people with persistently low blood oxygen levels.
LTOT may be used for extended periods each day according to medical recommendations and individual clinical requirements. The objective is to maintain appropriate oxygenation over the long term as part of a broader respiratory care plan.
The decision to prescribe LTOT is based on clinical assessment, diagnostic testing and ongoing specialist evaluation.
What oxygen therapy systems are available for home use?
Several oxygen delivery options are available depending on lifestyle requirements and prescribed oxygen needs.
Liquid oxygen systems
Liquid oxygen is stored at extremely low temperatures and expands into gaseous oxygen when released.
These systems can provide substantial oxygen capacity while supporting mobility for eligible patients.
Stationary oxygen concentrators
Stationary oxygen concentrators extract oxygen from room air and provide a continuous oxygen supply for home use.
They are commonly used as a primary oxygen source in long-term therapy.
Portable oxygen concentrators
Portable oxygen concentrators are designed to support mobility and travel while providing supplemental oxygen.
Battery-powered operation allows greater flexibility for daily activities outside the home.
Explore portable oxygen concentrators
Living an active life with oxygen therapy
Many people assume oxygen therapy will significantly restrict their independence. Modern oxygen equipment is increasingly designed to support mobility and daily activities while maintaining treatment continuity.
Practical preparation, proper equipment use and ongoing support can help patients continue many aspects of everyday life, including social activities, travel and time spent outdoors, according to their healthcare team's recommendations.
At Linde Homecare, patients and caregivers can access educational resources, oxygen therapy equipment, respiratory support services and information designed to support long-term respiratory care at home.
Supporting respiratory health over the long term
Oxygen therapy is only one part of managing chronic respiratory disease. Regular follow-up, adherence to prescribed treatments, healthy lifestyle choices and ongoing communication with healthcare professionals all contribute to long-term care.
With the right support and equipment, many people can successfully integrate oxygen therapy into their daily routine while maintaining independence and quality of life.