Low blood oxygen levels provide important and early indicators of poor respiratory health and deterioration. That’s why it’s important to understand your levels and act on them quickly.

Understanding blood oxygen

Blood oxygen levels indicate the amount of oxygen saturation in the blood. This helps you assess the presence of hypoxemia (low oxygen levels). It is also used by healthcare professionals to establish diagnosis and severity of heart disease.

Measuring your blood oxygen levels regularly is a good way to track your respiratory health and spot any deterioration. This can help to ensure more timely medical intervention if required.

Who needs to keep track of their blood oxygen levels?

While anyone concerned with the status of their health may wish to keep track of their blood oxygen levels, it’s particularly relevant for specific groups:

  • People with health conditions that compromise lung function – such as COPD (chronic obtrusive pulmonary disease) and sleep apnoea
  • People with temporarily compromised respiratory function due to illness (e.g. pneumonia or Covid-19)
  • People who suffer from cardiovascular diseases
  • Athletes wishing to track their performance levels, or who are engaging in high altitude activities (e.g. hiking and mountaineering)

How to get a reading from a finger-clip pulse oximeter

Using a pulse oximeter is simple and can be done from home without the assistance of a medical professional.

The first step is to wash your hands. Also, make sure the finger you’re going to use is free of nail polish or a false nail.

Make sure your hand is warm to the touch – rest it on your chest for 5 mins to make sure.

Attach the clip to your index finger (between your thumb and middle finger). Make sure your finger is fully inserted and not pressed hard into a surface. Turn the device on and keep your finger steady.

When the pulse oximeter displays your reading, write the numbers down in your diary. One measures how fast your heart is beating (BPM) and the other measures how much oxygen is in your blood.

What’s normal?

A ‘normal’ heart rate changes with age:*

Newborn–2 years: 100–180 bpm

2–10years: 60–140 bpm

10 years–adult: 50-100 bpm

But with blood oxygen levels (SpO2), while 95% or above is typically considered normal, it’s not always clear cut, as we discuss in the next section.

*Source: who.int

What constitutes low blood oxygen levels?

According to the World Health Organisation, oxygen saturation ≥ 95% is considered normal in people aged 12 years or older

Oxygen Saturation Levels
ReadingABG Level*O Sat result**
Below Normal< 80 mm Hg< 95%
Normal> 80 mm Hg95% to 100%

*Source: who.int
*Arterial Blood Gas
**Oxygen Saturation

However, with diseases such as COPD or other lung diseases, these ranges may not apply. For example, people with severe COPD may maintain their SpO2 levels between 88-92%. A doctor or consultant will be able to advise on the normal range their specific condition.

Be advised that below normal blood oxygen levels (hypoxemia) can be extremely serious, potentially causing complications in body tissue and organs. You should always consult a medical professional if reading falls below the normal range.

What can cause a drop in oxygen levels?

Low blood oxygen levels are a key indicator for compromised lung function, such as COPD (chronic obtrusive pulmonary disease) and sleep apnoea. It might also be a sign that respiratory function is temporarily compromised, often due to a temporary illness such as pneumonia.

Those with Covid-19 may also have low blood oxygen levels, even if they feel relatively well. Low oxygen levels can be an early warning sign to get tested or seek medical care.

It’s important to note that while Covid-19 may cause someone to have low blood oxygen levels, low blood oxygen levels in themselves are not necessarily indicative of infection. If you are worried, get tested or seek medical advice, especially if you have been near someone with the illness.

What is a pulse oximeter?

A pulse oximeter accurately measures oxygen saturation, pulse rate, and pulse amplitude, enabling users to track their respiratory health.

In more detail:

The principle of pulse oximetry is based on the difference in the selective absorption of red light by oxygenated blood compared to deoxygenated blood.

They work by transmitting a red and infrared light through a person’s finger and onto a detector inside a finger clip. This detects how much of the light has been absorbed by the oxygenated blood. The transmitted light is then analysed using a microprocessor which provides a % spO2 value.

These devices have been used by medical professionals for almost 50 years, although the technology has moved on significantly in that time. Devices have been adapted for home use and are now smaller, cheaper, easier to use and more accurate.

Leading the sector – the Braun Pulse oximeter 1

The Braun Pulse oximeter 1 is the ideal choice for customers for various reasons.

Key benefits:

  • Measures oxygen levels with clinically validated accuracy (meeting European standards CE)
  • Built to last, with a 2-year warranty
  • Trusted, well-known brand

Key features:

  • Comfortable finger clip design
  • Back-lit OLED display – for easy viewing and reading
  • Simple, push-button, rotating display – 4 different directions, 6 different displays
  • Automatic shut-off when the finger is removed

How to promote normal oxygen levels in your blood

There are several ways you can help your body improve blood oxygen retention.
Here are some starters for ten:*

  • Fresh air – Spending time outside, going for walks or even just opening the window can help increase oxygen availability to your lungs
  • Quit smoking – in just two weeks, people who have given up cigarettes find that circulation and overall oxygen levels improve significantly
  • Grow plants – certain houseplants can remove carbon dioxide and emit oxygen into your home
  • Do some breathing exercises – 'yoga' style deep breathing exercises can open your airways and increase oxygen intake

*Source: who.int