What does the medical abbreviation sats mean?

Sats stands for oxygen saturations. It is a measure of the amount of oxygen in the blood. Sats are usually measured using a pulse oximeter, which is a small device that clips onto a finger. The pulse oximeter shines a light through the finger and measures the amount of light that is absorbed by the blood. The amount of light that is absorbed depends on the amount of oxygen in the blood, so the pulse oximeter can calculate the saturations. Sats are usually measured in percentage points, with 100% being the highest possible value.