Electrodermal Activity

Electrodermal Activity is the electrical conductance of the skin. Apple describes conductance as increasing with sweat-gland activity. HealthKit stores this as a discrete quantity, rather than a category label such as calm or stressed.

Conductance is different from electrical resistance. A reading in ohms is not interchangeable with a reading in siemens by relabeling it. Confirm units before combining exports or comparing values from different sources.

The quantity alone does not identify an emotion, a stress disorder or a clinical condition. HealthKit supplies a place to store conductance; it does not standardize every device's sensor placement, measurement procedure or interpretation. A source may expose additional derived scores, but those scores should not be silently substituted for the conductance quantity.

For a useful comparison, retain the source, device and measurement procedure when known. Changes in the recording setup can interrupt a trend even when the chart appears continuous. Avoid a universal normal range across unverified sources.

There is no universal HealthKit sampling interval for this type. Start-to-start gaps describe what the writing source saved, and the gaps may differ from its internal sensor sampling. Review repeated timestamps, changes in intervals and periods without records before summarizing a day.

An ordinary mean gives each saved reading equal weight. If a source saves more readings during some periods, that mean emphasizes those periods. A time-weighted summary requires a justified rule for how long each observation represents; it cannot assume every gap is covered.

If both quantities are available, align observations within a stated time window and retain source boundaries. Co-recorded changes can describe a pattern, but matching timestamps do not establish why it occurred or validate a stress score.

No electrodermal activity records were found in the selected database window. This HealthKit type is not listed in the current PulsHealth sync catalog. Database coverage does not establish whether corresponding entries exist in Apple Health. No measured ranges, recording intervals or source comparisons are available from this example.