Health Journal and Apple Health data in HealthLab

The Journal is a dedicated tab in HealthLab for logging health events: measurements, symptoms, side effects, and as-needed medication intakes. It has three sections — Records, Trends, and Analytics. Adding an entry takes one tap on “Add Entry” and a choice of entry type. Records and Trends are free. Analytics, with an adherence percentage and correlations, is Pro.

The Journal is not the same thing as the medication intake log and adherence calendar. The intake log tracks scheduled medication courses on a schedule. The Journal is a more general log of health events — measurements, symptoms, side effects, and as-needed doses that aren’t tied to any schedule at all.

What to record and where to find it

The table below is a quick reference: what you can log in the Journal, which section it lives in, and which tier it requires.

The four entry types cover different situations: a measurement records a number (temperature or weight) at a specific moment; a symptom captures a subjective sensation that isn’t tied to any medication schedule; a medication intake for a symptom logs a one-off dose from your medicine cabinet, taken because something came up rather than because a course called for it; and a side effect flags a reaction worth noting separately and, if needed, discussing with a doctor.

How to use the Journal

Step 1. Open the Journal and add an entry

In the Journal tab, tap “Add Entry” and choose a record type: a measurement (temperature, weight), a symptom, an as-needed medication intake for a symptom — a PRN dose drawn from your medicine cabinet — or a side effect. Each entry type has its own fields, so logging one takes only a few seconds. (Free)

Step 2. Review Records

The Records section lists every entry chronologically — measurements, symptoms, PRN doses, and side effects together in one timeline. This is the main event log: it’s worth checking before a doctor’s appointment to reconstruct the sequence of events, rather than relying on memory alone. (Free)

Step 3. Connect Apple Health and read Trends

If you’ve granted access to Apple Health, the Trends grid and its 90-day charts show the metrics the app has read, alongside your own Journal entries. This lets you see self-reported entries and Apple Health data in one place, without switching between apps or checking a separate health tracker. (Free)

Step 4. Open Analytics

Analytics shows the adherence percentage and medication↔symptom correlations, behind a paywall with a lock icon — unlocked by a Pro subscription. Both figures are computed from the same entries you’ve already made in Records — there’s nothing extra to enter, just keep using the Journal as usual. (Pro)

Apple Health data: the app only reads

HealthLab only reads data from Apple Health. Writing to Apple Health is disabled — the app never sends anything back or changes anything there. This is worth stating up front: the Apple Health connection in HealthLab is strictly one-directional.

Metrics the app reads, grouped as:

• cardio — resting heart rate, heart rate variability (HRV), VO₂ max;
• oxygen and respiration;
• sleep — duration and stages: deep, core, REM. When poor sleep keeps recurring for weeks, this sleep data is worth reviewing alongside insomnia blood tests — the Journal shows the sleep pattern, not the cause;
• body — weight, height, body-fat percentage, waist circumference;
• activity — steps, energy burned, exercise minutes.

These metrics appear in the Trends grid and its 90-day charts, alongside your own Journal entries — the measurements, symptoms, and side effects you log by hand. The Health Score on the home screen is also computed from the Apple Health metrics.

Scenario: a new medication course and a recurring evening headache

Someone starts a new medication for a two-week course. At the same time, a headache keeps recurring in the evenings for several days in a row. Rather than relying on memory by the end of the course, each headache episode is logged as a symptom, and each as-needed dose of a painkiller is logged as a medication intake for a symptom. Within a few days, Records shows the sequence: when the headache appeared, how often the painkiller was needed, and whether that lines up with the start of the new course, instead of a vague sense that “it’s been happening a lot lately.” This describes a pattern over time — it does not draw a medical conclusion about the cause. The final interpretation of it is a doctor’s job, not the app’s, and these entries can simply be shown to the doctor at the appointment instead of being recalled from memory.

Edge cases

• Apple Health permission not granted. The Journal’s own records — measurements, symptoms, PRN doses, side effects — keep working without any limitation, since none of the four entry types require Apple Health access at all.
• A metric your iPhone has no data for. For instance, if nothing on the phone measures VO₂ max, the corresponding part of the Trends grid shows a “no data” placeholder for that period rather than an error. The rest of the metrics and your own Journal entries display as usual.
• An entry added after the fact. “Add Entry” lets you set the date and time of the event, not only the current moment — useful if you’re logging a symptom the next morning rather than as soon as it appeared, and you want Records to keep the correct order of events.

Free and Pro in the Journal

Records (all four entry types — measurement, symptom, medication intake for a symptom, side effect) and Trends, including the Apple Health grid and its 90-day charts, are Free and available without a subscription right after installing the app. Analytics — the adherence percentage and medication↔symptom correlations — is Pro, behind a lock icon.

Don’t confuse this with the adherence calendar for scheduled medication courses, which is a separate, free feature of the medication intake log and adherence calendar and shows whether scheduled doses were taken on time. The adherence percentage in the Journal’s Analytics is a different, Pro feature: it’s calculated from the general event log, not only from scheduled courses.

Because medication↔symptom correlations invite interpretation, it’s worth keeping the app’s boundary in mind: the app is not a medical device and does not provide medical advice, diagnoses, or treatment recommendations. The final read on any pattern belongs to a doctor, not an algorithm.

Frequently asked questions

HealthLab for the full picture

The Journal complements the medications and courses section: one tool tracks scheduled doses and a course’s own schedule, the other tracks free-form health events, symptoms, and Apple Health data. Both stay stored locally on your device, with no account required, and together they give a more complete picture than either does alone: the schedule shows what was planned, and the Journal shows what actually happened.

Try HealthLab and start keeping a Journal alongside your lab results and medication courses — all in one app, with no registration required and no medical data sent to third-party servers.