Hydration · User guide
Your Hydration Result
How BodyCheck reads your water status and chloride together, and what each result means.
See the result table
Understanding your result
Every time you test, BodyCheck reads two things from your urine:
How concentrated it is — this reflects your water status: are you topped up, or running dry? We report it as one of four hydration levels.
Your chloride level — chloride is a key electrolyte you lose when you sweat. We compare it to your own usual range and report it as Normal or Low.
Reading the two together tells you more than a simple "drink more water" reading can. Water status on its own can mislead — for example, drinking a lot of plain water can make you look perfectly hydrated while quietly flushing out electrolytes. The chloride reading catches that.
Your result is most useful over time. A single test is a snapshot; your trend is the real picture.
The four hydration levels
Based on how concentrated your urine is:
| Your reading | Specific gravity | What it means |
|---|---|---|
| Very well hydrated | 1.000 – 1.005 | Very dilute — you're well topped up on fluids. |
| Well hydrated | 1.005 – 1.020 | A healthy, balanced level. |
| Slightly under-hydrated | 1.020 – 1.027 | A little concentrated — a good time for a glass of water. |
| Under-hydrated | 1.027 and above | Concentrated — time to rehydrate. |
Your chloride level
Chloride is compared to your own baseline — the range BodyCheck learns from your recent tests — not to a fixed number (see Why we compare chloride to your own baseline below).
| Your reading | What it means |
|---|---|
| Normal | Your chloride is within your usual range. |
| Low | Your chloride is below your usual range — your body may be holding on to salt, or you may be running low. |
Your chloride reading needs about 5 testing days to learn your baseline. Until then, you'll see your hydration level only, and the chloride reading will show that it's still warming up. If you go a long time between tests (more than about a week), the chloride reading is shown as an estimate until your baseline catches up — so test at least every 2–3 days, first thing in the morning, to keep it accurate.
Your result at a glance
Find your hydration level down the side and your chloride reading across the top.
Very well hydrated
Well hydrated
Slightly under-hydrated
Under-hydrated
Why we compare chloride to your own baseline, not a fixed number
Unlike body temperature, there's no single "normal" level of chloride in urine that works for everyone. How much shows up in any one sample depends on two things at once: how much salt you've eaten and how concentrated your urine is that day. Both change constantly, and even perfectly healthy people vary widely — from one person to the next, and from day to day in the same person.
A fixed "normal range" would therefore be misleading. It would flag a salty dinner as a problem, or miss a real dip because your number still landed inside a broad one-size-fits-all band.
So instead, BodyCheck learns your usual range from your first several tests and watches for when a reading drifts below it. "Low" means low for you — far more meaningful than low compared to a stranger. To keep the comparison fair, we also account for how concentrated each sample is (using creatinine), so a dilute or concentrated test doesn't throw the reading off.
This is why your chloride reading:
- takes a few tests to warm up,
- works best when you test regularly — at least every 2–3 days, first thing in the morning, and
- pauses or shows an estimate after a long gap, until it re-learns your baseline.
We focus on spotting when your chloride runs low, because that's the direction you can act on — your cue to reach for electrolytes alongside water.
BodyCheck is a general wellness product to help you track and maintain healthy hydration. It is not a medical device and does not diagnose, treat, or prevent any condition. If you have health concerns, talk to a healthcare professional.
Data is only as powerful as your ability to use it.
Put the science to work. Measure your hydration instead of estimating it.
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