lowHeartRateEvent: HealthKit category type
HKCategoryTypeIdentifierLowHeartRateEvent · read from Apple’s documentation on 2026-10-02
HKCategoryTypeIdentifier.lowHeartRateEvent (Objective-C HKCategoryTypeIdentifierLowHeartRateEvent) is a HealthKit category type in Apple's "Vital Signs" group. Apple's abstract: “A category sample type for low heart rate events.” Apple's page names the generic HKCategoryValue for its sample values rather than an enum of its own. Apple states that apps cannot save it: “The low heart rate samples are read-only.” It is available from iOS 12.2 and watchOS 5.2.
What Apple says lowHeartRateEvent is
A category sample type for low heart rate events.
Apple’s abstract, quoted from its lowHeartRateEvent reference page, read 2026-10-02. Apple’s discussion of the type runs 91 words.
- Swift
HKCategoryTypeIdentifier.lowHeartRateEvent- Objective-C
HKCategoryTypeIdentifierLowHeartRateEvent- Family
HKCategoryTypeIdentifier- Apple's topic group
- Vital Signs
- Group page
- Vital signs
- Apple's reference
- lowHeartRateEvent on developer.apple.com
Availability
The versions Apple’s documentation data gives for lowHeartRateEvent, platform by platform, as read on 2026-10-02.
| Platform | Introduced | Deprecated |
|---|---|---|
| iOS | 12.2 | — |
| iPadOS | 12.2 | — |
| Mac Catalyst | 13.0 | — |
| macOS | 13.0 | — |
| visionOS | 1.0 | — |
| watchOS | 5.2 | — |
The rest of that release: HealthKit Types Introduced in iOS 12.
What a sample holds
Value enum
HKCategoryValue — the enum Apple’s page for lowHeartRateEvent names: the generic one, not one of its own. Every category type’s enum is on the HKCategoryValue reference.
Aggregation style and unit family apply only to quantity types. For a category type the dataset records neither, because the concept does not apply — not because Apple declined to say.
Can apps write lowHeartRateEvent?
No. Apple’s documentation states that these samples are read-only:
The low heart rate samples are read-only.
On Android Health Connect
No verified Health Connect counterpart. The cross-platform matrix pairs only metrics checked against both Apple’s and Google’s documentation, and lowHeartRateEvent is not among them. A similarly named Health Connect record may exist, but a name match is not a verified mapping.
Questions
- Which enum decodes lowHeartRateEvent sample values?
- The generic HKCategoryValue. Apple's page for lowHeartRateEvent names it rather than an enum of its own; this site's HKCategoryValue reference lists every category type that resolves the same way and what that means for reading the samples.
- Can my app write lowHeartRateEvent samples to HealthKit?
- No. Apple's documentation for lowHeartRateEvent states: "The low heart rate samples are read-only." (read 2026-10-02).
- Which iOS version added lowHeartRateEvent?
- iOS 12.2. Apple's availability data for lowHeartRateEvent lists iOS 12.2, iPadOS 12.2, Mac Catalyst 13.0, macOS 13.0, visionOS 1.0 and watchOS 5.2.
Sources checked
- Apple — HKCategoryTypeIdentifier.lowHeartRateEvent · read 2026-10-02
- Apple — HKCategoryTypeIdentifier · read 2026-10-02
Apple’s abstract and sentences are quoted for identification; the page layout, the capsule and the cross-platform pairing are AIFitnessAPI’s. Generated from Apple’s documentation by scripts/fetch-healthkit-identifiers.mjs, not typed by hand — the same data as the full identifier table.