<!--
{
  "availability" : [
    "iOS: 8.0.0 -",
    "iPadOS: 8.0.0 -",
    "macCatalyst: 13.0.0 -",
    "macOS: 13.0.0 -",
    "visionOS: 1.0.0 -",
    "watchOS: 2.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "HealthKit",
  "identifier" : "/documentation/HealthKit/HKBloodType",
  "metadataVersion" : "0.1.0",
  "role" : "Enumeration",
  "symbol" : {
    "kind" : "Enumeration",
    "modules" : [
      "HealthKit"
    ],
    "preciseIdentifier" : "c:@E@HKBloodType"
  },
  "title" : "HKBloodType"
}
-->

# HKBloodType

Constants indicating the user’s blood type.

```
enum HKBloodType
```

## Topics

### Constants

[`HKBloodTypeNotSet`](/documentation/HealthKit/HKBloodType/notSet)

Either the user’s blood type is not set, or the user has not granted your app permission to read the blood type.

[`HKBloodTypeAPositive`](/documentation/HealthKit/HKBloodType/aPositive)

The user has an A+ blood type.

[`HKBloodTypeANegative`](/documentation/HealthKit/HKBloodType/aNegative)

The user has an A– blood type.

[`HKBloodTypeBPositive`](/documentation/HealthKit/HKBloodType/bPositive)

The user has an B+ blood type.

[`HKBloodTypeBNegative`](/documentation/HealthKit/HKBloodType/bNegative)

The user has an B– blood type.

[`HKBloodTypeABPositive`](/documentation/HealthKit/HKBloodType/abPositive)

The user has an AB+ blood type.

[`HKBloodTypeABNegative`](/documentation/HealthKit/HKBloodType/abNegative)

The user has an AB– blood type.

[`HKBloodTypeOPositive`](/documentation/HealthKit/HKBloodType/oPositive)

The user has an O+ blood type.

[`HKBloodTypeONegative`](/documentation/HealthKit/HKBloodType/oNegative)

The user has an O– blood type.

## Relationships

### Conforms To

[`Sendable`](/documentation/Swift/Sendable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Equatable`](/documentation/Swift/Equatable)

[`Hashable`](/documentation/Swift/Hashable)

[`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable)

[`RawRepresentable`](/documentation/Swift/RawRepresentable)

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)