Oxygen Saturation

What it is

Oxygen saturation, often referred to as 'Sats', is a measure of how much oxygen your blood is carrying. Specifically, it tells you the percentage of haemoglobin in your red blood cells that is carrying oxygen. Haemoglobin is a protein found in red blood cells that is responsible for transporting oxygen from your lungs to the rest of your body, and also for carrying carbon dioxide back to your lungs to be exhaled.

Think of haemoglobin as tiny taxis in your bloodstream. When these taxis pick up oxygen in your lungs, they become 'saturated'. Oxygen saturation measures how many of these taxis are carrying oxygen. A normal reading typically falls between 95% and 100%.

This measurement is usually taken using a small device called a pulse oximeter, which clips onto a fingertip, earlobe, or toe. It's a quick and painless way to get an indication of how well your lungs and circulatory system are working together to deliver oxygen to your body.

Why it matters

Oxygen is essential for life. Every cell in your body needs a constant supply of oxygen to function correctly. It's used in a process called cellular respiration, which generates the energy your body needs to perform all its activities, from thinking and moving to repairing tissues and fighting off infections.

When your oxygen saturation levels are within the normal range (typically 95-100%), it suggests that your body is receiving an adequate supply of oxygen. If your oxygen saturation drops below this range, it can indicate that your body isn't getting enough oxygen. This can be a sign that there might be an issue with your lungs, heart, or circulation, or even with the air you are breathing.

Monitoring oxygen saturation can be particularly important for individuals with certain health conditions, such as lung diseases (like asthma or COPD), heart conditions, or during and after surgery. It helps healthcare professionals assess how well treatments are working and to detect potential problems early.

What can cause it to be high or low

High Oxygen Saturation:

It's very rare for oxygen saturation to be too high. In most healthy individuals, the reading will naturally sit at the top end of the normal range (95-100%). Occasionally, readings slightly above 100% might be seen in specific circumstances, such as when someone is receiving supplemental oxygen, but this is usually not a cause for concern in itself.

Low Oxygen Saturation:

A lower-than-normal oxygen saturation reading (below 95%) can be associated with a variety of factors affecting the lungs, heart, or blood.

• Lung conditions: Problems with the lungs themselves can impair their ability to take in oxygen and transfer it to the blood. This can include conditions like pneumonia (infection of the lungs), chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis (scarring of the lungs), or a pulmonary embolism (a blood clot in the lungs).
• Heart conditions: If the heart isn't pumping blood effectively, oxygenated blood may not be circulated efficiently throughout the body. Certain congenital heart defects can also affect oxygen levels.
• Circulatory issues: Conditions that affect blood flow, such as severe anaemia (a lack of red blood cells or haemoglobin), can mean there's less capacity to carry oxygen.
• Airway obstruction: Anything that blocks the airways, such as choking or severe swelling, can reduce the amount of oxygen reaching the lungs.
• Sleep apnoea: This condition involves pauses in breathing during sleep, which can lead to drops in oxygen saturation.
• High altitude: At higher altitudes, the air has less oxygen, which can naturally lower oxygen saturation levels.
• Certain medications: Some medications, particularly strong painkillers or sedatives, can sometimes affect breathing and, consequently, oxygen saturation.

Lifestyle factors that may help

For individuals looking to support healthy oxygen levels, certain lifestyle choices can be beneficial. These are often discussed with healthcare professionals as part of an overall wellness plan.

• Regular physical activity: Engaging in moderate exercise, as advised by your doctor, can improve lung capacity and cardiovascular health, which are vital for efficient oxygen transport. Activities like brisk walking, swimming, or cycling can be helpful.
• Maintaining a healthy weight: Being overweight or obese can put extra strain on your respiratory and cardiovascular systems. A balanced diet and regular exercise can help manage weight.
• Avoiding smoking: Smoking damages the lungs and airways, significantly impairing their ability to transfer oxygen. Quitting smoking is one of the most impactful steps for improving lung health and oxygen saturation.
• Practising good respiratory hygiene: Simple measures like washing hands regularly can help prevent respiratory infections that can affect oxygen levels.
• Breathing exercises: Techniques such as diaphragmatic breathing (belly breathing) or pursed-lip breathing can sometimes help improve the efficiency of breathing and oxygen intake. These are often taught by respiratory therapists.
• Ensuring good indoor air quality: Avoiding exposure to pollutants, dust, and smoke indoors can help keep your lungs healthier.

Questions to discuss with your GP

If you have concerns about your oxygen saturation, or if it has been measured as low, it's always best to have a conversation with your GP. Here are some questions you might consider discussing:

• What is my typical oxygen saturation range, and what do these readings mean for my health?
• Are there any specific lung or heart conditions that might be affecting my oxygen levels?
• What are the most common causes of low oxygen saturation in my particular situation?
• Are there any lifestyle changes or specific exercises that could help improve my oxygen saturation?
• If I need to monitor my oxygen saturation at home, what kind of device should I use, and how often should I check it?
• What symptoms should I watch out for that might indicate a significant drop in my oxygen levels?