Oxygen saturation (medicine)

Oxygen saturation is a way to measure how much oxygen is in your blood. It is important because your body needs oxygen to work properly.

Think of your blood like a tiny swimming pool that carries oxygen and other things around your body. The oxygen attaches to a special part of your blood called hemoglobin.

When a doctor or nurse measures your oxygen saturation, they put a small device on your finger called a pulse oximeter. This device shines a light through your finger and measures how much of that light is absorbed by your blood.

When your blood is full of oxygen, it absorbs the light differently than when it doesn’t have enough oxygen. The pulse oximeter can read this and tell the doctor or nurse your oxygen saturation percentage.

For example, if your oxygen saturation is 98%, it means that out of every 100 little hemoglobin swimming around in your blood, 98 of them have oxygen attached to them.

Doctors use this measurement to make sure you are getting enough oxygen. If your oxygen saturation is too low, it can be a sign that there is something wrong and you may need extra help to breathe or get more oxygen into your body.