Characteristic types represent data that does not typically change over time.


The HKCharacteristicType class is a concrete subclass of the HKObjectType class. To create a characteristic type instance, use the object type’s characteristicType(forIdentifier:) convenience method.

Unlike the other object types, characteristic types cannot be used to create and save new HealthKit objects. Instead, users must enter and edit their characteristic data using the Health app. Similarly, you cannot create queries for characteristic types. Instead, use the HealthKit store to access the data (see Reading Characteristic Data).

HealthKit provides five characteristic types: biological sex, blood type, birthdate, Fitzpatrick skin type, and wheelchair use. These types are used only when asking for permission to read data from the HealthKit store.


Inherits From

Conforms To

See Also

Type Objects

class HKQuantityType

Quantity types identify samples that store numerical values.

class HKCategoryType

Category types identify samples that contain a value from a small set of possible values.

class HKCorrelationType

Correlation types identify samples that group multiple subsamples.

class HKActivitySummaryType

Activity summary types identify activity summary objects.

class HKSeriesType

An identifier that indicates the type for data stored in a series sample.

class HKObjectType

The abstract superclass for all classes that identify a specific type of data when working with the HealthKit store.

class HKSampleType

An abstract superclass for all classes that identify a specific type of sample when working with the HealthKit store.