breathing blood test explained
Informed by recognized medical guidance
Overview
A breathing blood test (also called an arterial blood gas test or ABG) checks how well your lungs are getting oxygen into your blood and removing carbon dioxide. It also measures the acidity (pH) of your blood. This test helps doctors understand if you have a lung or breathing problem.
Key facts
- The test uses a small sample of blood from an artery, usually in your wrist.
- It gives quick results about oxygen, carbon dioxide, and blood pH levels.
- A breathing blood test can show if you need extra oxygen or help with breathing.
This test is common in hospital emergency rooms, intensive care units, and pulmonary (lung) clinics. It is not a routine test for everyone, but it is often done when someone has serious breathing difficulties.
It is used for people of any age who have breathing problems, such as from asthma, COPD, pneumonia, or a severe allergic reaction. It is also used to monitor patients on ventilators (breathing machines) or with conditions that affect blood acidity.
Symptoms
- You or someone with you stops breathing or is gasping for air
- Severe chest pain accompanied by difficulty breathing
- Sudden blue or grey colour of the face, lips, or tongue
- Unconsciousness or unresponsiveness
- ⚠New or worsening shortness of breath that does not improve with rest
- ⚠Breathing that becomes faster or slower than normal over a short time
- ⚠Dizziness, fainting, or confusion along with breathing trouble
Common symptoms
- Shortness of breath or feeling like you cannot get enough air
- Rapid breathing (tachypnea)
- Chest tightness or wheezing
- Confusion or drowsiness (signs of low oxygen or high carbon dioxide)
- Bluish color of lips or fingertips (cyanosis)
Symptoms in children
- Faster breathing than normal for their age
- Flaring nostrils or using chest/stomach muscles to breathe
- Grunting sounds while breathing
- Irritability or difficulty feeding
Symptoms in older adults
- Increased breathlessness with activity or at rest
- Confusion or sudden tiredness
- Faster or slower than normal breathing rate
Causes
Main causes
- Lung diseases like asthma, chronic obstructive pulmonary disease (COPD), or pneumonia
- Heart failure or other heart conditions that affect oxygen delivery
- Severe infections (sepsis) that affect breathing and blood acidity
- Drug overdose or poisoning that slows breathing
- Kidney failure or other metabolic problems that change blood pH
Risk factors
- Smoking or exposure to air pollution
- Chronic lung conditions
- Recent surgery, especially on the chest or abdomen
- Obesity (can affect breathing during sleep)
- Weakened immune system (higher risk of infections)
When to see a doctor
See a doctor urgently if:
- You have sudden or severe shortness of breath that does not go away
- You feel like you are about to faint or cannot stay awake
- You have a bluish tint to your lips or skin
Book a routine appointment if:
- You have ongoing breathing problems, like a cough or wheeze that lasts for weeks
- You feel more tired or breathless than usual during daily activities
- You have a chronic lung condition and need to check how well your treatment is working
Diagnosis
The breathing blood test is done by taking a small amount of blood from an artery (usually in your wrist). The sample is sent to a lab, and results are usually available within a few minutes to an hour. The test measures oxygen level, carbon dioxide level, and blood pH.
Tests that may be done
- Arterial blood gas (ABG) test – the main test for breathing and blood acidity
- Pulse oximetry – a simple clip on your finger that estimates oxygen level (but ABG is more detailed)
- Chest X-ray or CT scan – to look for lung problems causing abnormal ABG results
- Lung function tests (spirometry) – to see how well your lungs move air in and out
What to expect at your appointment
You will be awake. A healthcare provider will feel for a pulse in your wrist, clean the area, and insert a very thin needle to collect a small amount of blood. You may feel a brief sharp sting. Afterward, pressure is applied to the site to stop any bleeding. The whole procedure takes only a few minutes.
Treatment
Treatment for abnormal breathing blood test results depends on the underlying cause. The goal is to improve oxygen levels, reduce carbon dioxide, and correct blood acidity. Your doctor will create a plan based on your specific condition.
Self-care at home
- If you have a chronic lung condition, take your prescribed medicines as directed by your doctor
- Avoid smoking and second-hand smoke
- Practice deep breathing exercises if recommended by a respiratory therapist
- Stay active as much as your condition allows – ask your doctor about safe exercises
Medical treatments
Medical treatments may include oxygen therapy (extra oxygen through a mask or nasal tubes), medicines to open the airways (bronchodilators) or reduce inflammation (corticosteroids), and in severe cases, non-invasive breathing support (like a CPAP or BiPAP machine) or a ventilator (breathing machine). For infections, antibiotics or antivirals may be given. For metabolic causes (like kidney problems), treatments to correct pH balance may be used.
When is surgery considered?
Surgery is rarely needed for the breathing blood test itself. It may be needed if a lung condition (such as a collapsed lung or lung mass) requires surgical intervention. Your doctor will advise if surgery becomes an option for your underlying condition.
Living with this condition
If you have a condition that requires regular breathing blood tests, you may need to visit a pulmonary clinic or hospital for monitoring. You can learn to manage your symptoms with your healthcare team’s support. Many people with chronic lung conditions lead active lives with proper treatment.
Lifestyle tips
- Follow your treatment plan exactly as prescribed
- Learn your early warning signs (such as increased breathlessness or change in sputum) so you can act quickly
- Keep a list of your medicines and share it with all your doctors
- Get recommended vaccinations (flu, pneumonia, COVID-19) to reduce infection risk
Diet and exercise
A well-balanced diet helps maintain strength. If you have COPD or other lung conditions, a dietitian may suggest smaller, more frequent meals to avoid feeling too full and breathless. Exercise, such as walking or pulmonary rehabilitation, can improve your ability to breathe and your quality of life. Always check with your doctor before starting a new exercise program.
Mental health and emotional wellbeing
Living with a breathing problem can be stressful and sometimes frightening. It is normal to feel anxious or depressed. Talk to your healthcare provider about these feelings – they can connect you with counselling, support groups, or mental health specialists. Remember that you are not alone.
Prevention
Many conditions that require a breathing blood test cannot be fully prevented, but you can reduce your risk by avoiding smoking, staying active, and managing chronic illnesses like asthma or heart disease. Good hand hygiene and vaccinations can help prevent infections that lead to breathing problems.
Vaccines
Vaccines against influenza (flu), pneumococcal disease (pneumonia), and COVID-19 are recommended for people with chronic lung conditions. Ask your doctor which vaccines are right for you.
Screening programmes
There is no routine screening test for all breathing problems. If you have risk factors (like smoking or family history of lung disease), your doctor may recommend regular check-ups or lung function tests. The breathing blood test is only done when there is a specific concern.
Complications
If left untreated
- Low oxygen can damage organs such as the heart, brain, and kidneys
- High carbon dioxide can cause confusion, drowsiness, or coma
- Severe acid-base imbalance can lead to shock or organ failure
- Delayed treatment of an underlying lung infection may spread or become life-threatening
Long-term outlook
With proper treatment and monitoring, many people with breathing problems improve and maintain good quality of life. The breathing blood test helps guide treatment so that oxygen and acid levels are corrected quickly. The outlook depends on the cause, but early diagnosis and care give the best chance of recovery.
Find support
International organisations
Local organisations
- Asthma + Lung UK ↗ · United Kingdom
External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.
Always verify with your doctor
Health guidelines vary by country and region. The information in this article is based on international clinical guidelines but may not reflect the specific guidelines, medications, or practices in your country. Always discuss your health concerns with your own doctor or healthcare provider, and refer to your local national health guidelines where available.
Important notice This information is for educational purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your specific situation. If you are experiencing a medical emergency, call your local emergency services immediately.
Related conditions
Sources and guidance
This article is educational and is prepared with reference to recognized health information and clinical guidance sources where available. Specific source links may vary by topic.
Last updated: July 16, 2026
Educational note: This information is for education only and is not a diagnosis.
Use it to support, not replace, advice from a licensed clinician.
If symptoms are severe, worsening, or urgent, call your local emergency number or seek emergency care.
Guidance may differ by country or region. Confirm local recommendations with a qualified healthcare provider.