Height

Height is a length measurement that can be entered manually or written by an app. Apple stores it as a discrete quantity. An app's profile height and a timestamped HealthKit height observation are separate pieces of evidence: one can exist without the other appearing in an export.

Use actual measured height for a calculation when available. The CDC measuring guide describes removing shoes and measuring standing height with an appropriate setup. Technique and units matter when comparing records.

An adult profile measurement may be updated only occasionally. Children being monitored for growth need a different interpretation. Repeated identical values might represent repeated profile writes rather than new measurements; a new timestamp does not itself establish growth or shrinkage.

The full-year research snapshot contained no raw height observations and no stored height aggregates. There is no measured height range, repeat-write frequency, outlier analysis or cadence curve from this study. Empty data within this window does not prove there is no older height record or height stored in a source app's profile.

Yes: the example includes BMI and weight written together even though no raw height observation appeared in the year. 218 exact-time, same-source pairs were mathematically consistent with a fixed height denominator. That denominator was calculated from the pair, not independently measured stature.

A source app may retain the height it uses without writing fresh height samples. This is a possible explanation, not verified producer behavior. Do not manufacture a Height record from BMI and weight or describe the derived denominator as an observed height.

There is no universal healthy height interval. Population percentiles describe a reference distribution, while growth assessment requires age-appropriate charts and repeated measurements. A broad number range should not be treated as a diagnostic boundary or a rule for discarding data.

BMI uses height squared with weight. Body-composition producers may also use profile inputs in their own models. Those dependencies do not establish that HealthKit has a contemporaneous height observation or that the input has been recently verified.

If a height-dependent result looks wrong, inspect the producer's current input and units as well as the Health records. Missing height in the export should remain an explicit limitation rather than being filled with an assumed value.