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# millimeterOfMercury()

Returns a HealthKit unit for measuring pressure in millimeters of mercury.

```
class func millimeterOfMercury() -> Self
```

## Return Value

A HealthKit unit for measuring pressure in millimeters of mercury.

## Discussion

One millimeter of mercury is the pressure needed to raise a column of mercury by 1 millimeter. Even through it is not an SI unit, the millimeter of mercury unit is used in many scientific fields. In HealthKit, it is commonly used to measure blood pressure.

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