Apple Develops Innovative Hydration Sensor for the Apple Watch

Apple has developed a first-of-its-kind hydration sensor designed for the Apple Watch, a company patent filing has revealed.

apple watch series 6 product red back
The patent, first spotted by Patently Apple, is titled "Hydration measurement with a watch" and was granted by the U.S. Patent and Trademark Office.

"Traditional techniques for tracking hydration are generally invasive, expensive, or unreliable," according to Apple. This refers to existing ways of determining hydration such as single-use tests of fluid samples.

Apple's hydration sensor takes the form of non-invasive electrodes that are placed against the skin, which it describes as a "reliable and elegant" solution. The sensor works by measuring the electrical properties of the Apple Watch wearer's sweat. The patent explains:

The electrical properties, such as electrical conductance, can represent a concentration of electrolytes in the perspiration, which in turn represents a hydration level of the user.

[...]

For example, a high level of electrical conductance of the perspiration can indicate a high concentration of electrolytes and a low level of hydration. By further example, a low level of electrical conductance of the perspiration can indicate a low concentration of electrolytes and a high level of hydration.

The filing goes on to give a lengthy and detailed technical description of the hydration sensor and its functionality.

Apple says that its hydration tracking system can be performed "non-invasively, repeatedly, accurately, automatically, and with minimal user intervention." According to the patent, hydration data may be used to provide feedback to the user, particularly during activity such as workouts, and encourage better management of water intake, and in turn, overall health. The filing outlines why hydration is a valuable health metric:

A user's hydration level has significant impacts on the health of a user. Dehydration can impair performance and is associated with several deleterious health consequences, including heat strokes. Overdrinking can result in hyponatremia, fatigue, confusion, coma, and even death.

Patent filings cannot be taken as firm evidence of Apple's plans, but they do show the company's areas of research. Nevertheless, Apple is known to have ambitious plans for adding new health tracking capabilities to the Apple Watch following the debut of blood oxygen monitoring with the Apple Watch Series 6 and hydration monitoring now appears to be a viable option for the company to add to the device in the future.

Related Roundup: Apple Watch 10
Tag: Patent
Buyer's Guide: Apple Watch (Caution)

Popular Stories

iPhone 17 Pro in Hand Feature Lowgo

iPhone 17 Pro Coming Soon With These 14 New Features

Friday July 4, 2025 1:05 pm PDT by
Apple's next-generation iPhone 17 Pro and iPhone 17 Pro Max are just over two months away, and there are plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models. Latest Rumors These rumors surfaced in June and July:Apple logo repositioned: Apple's logo may have a lower position on the back of the iPhone 17 Pro models, compared to previous...
Apple Watch Ultra Night Mode Screen

Apple Watch Ultra 3 Launching Later This Year With Two Key Upgrades

Wednesday July 2, 2025 1:13 pm PDT by
The long wait for an Apple Watch Ultra 3 appears to be nearly over, and it is rumored to feature both satellite connectivity and 5G support. Apple Watch Ultra's existing Night Mode In his latest Power On newsletter, Bloomberg's Mark Gurman said that the Apple Watch Ultra 3 is on track to launch this year with "significant" new features, including satellite connectivity, which would let you...
iPhone 17 Pro in Hand Feature Lowgo

iPhone 17 Pro Max Battery Capacity Leaked

Thursday July 3, 2025 5:40 am PDT by
The iPhone 17 Pro Max will feature the biggest ever battery in an iPhone, according to the Weibo leaker known as "Instant Digital." In a new post, the leaker listed the battery capacities of the iPhone 11 Pro Max through to the iPhone 16 Pro Max, and added that the iPhone 17 Pro Max will feature a battery capacity of 5,000mAh: iPhone 11 Pro Max: 3,969mAh iPhone 12 Pro Max: 3,687mAh...
airpods pro 2

AirPods Pro 3 to Help Maintain Apple's Place in Earbud Market Amid Increasing Low-Cost Competition

Thursday July 3, 2025 7:25 am PDT by
Apple's position as the dominant force in the global true wireless stereo (TWS) earbud market is expected to continue through 2025, according to Counterpoint Research. The forecast outlines a 3% year-over-year increase in global TWS unit shipments for 2025, signaling a transition from rapid growth to a more mature phase for the category. While Apple is set to remain the leading brand by...
iphone 16 pro models 1

Here's How the iPhone 17 Pro Max Will Compare to the iPhone 17 Pro

Saturday July 5, 2025 1:00 pm PDT by
Apple should unveil the iPhone 17 series in September, and there might be one bigger difference between the Pro and Pro Max models this year. As always, the Pro Max model will be larger than the Pro model:iPhone 17 Pro: 6.3-inch display iPhone 17 Pro Max: 6.9-inch displayGiven the Pro Max is physically larger than the Pro, it has more internal space, allowing for a larger battery and...
apple silicon mac lineup 2024 feature purple m5

Apple's Upcoming Macs Listed in New Report

Thursday July 3, 2025 9:09 am PDT by
AppleInsider's Marko Zivkovic today shared a list of alleged identifiers for future Mac models, which should roll out over the next year or so. The report does not reveal anything too surprising, but it does serve as further evidence that Apple is seemingly working on new models of every Mac, including the MacBook Air, MacBook Pro, iMac, Mac mini, Mac Studio, and Mac Pro. Apple is...

Top Rated Comments

farewelwilliams Avatar
51 months ago
it detects how thirsty you are for that MacBook Pro 16" redesign
Score: 22 Votes (Like | Disagree)
Shanghaichica Avatar
51 months ago
This looks useful. Still waiting for blood pressure though.
Score: 19 Votes (Like | Disagree)
jazz1 Avatar
51 months ago
Nice, but I'm waiting for blood sugar monitor. I hate the prick of the needle!!!
Score: 14 Votes (Like | Disagree)
TheYayAreaLiving ?️ Avatar
51 months ago
Woah! Apple watch just keeps getting better and better. However, I would want Apple to introduce body temperature sensor.
Score: 12 Votes (Like | Disagree)
Shanghaichica Avatar
51 months ago

The latest Samsung watch announced a week or so ago claims to have blood pressure capabilities…
They do. I‘ve used it on the samsung galaxy active 2. It works and its accurate when compared to a dedicated blood pressure machine.
Score: 7 Votes (Like | Disagree)
jefhai Avatar
51 months ago

This looks useful. Still waiting for blood pressure though.
Blood pressure will never happen unless Apple Watch has some kind of air compressor to verify systolic diastolic. Dental offices have wrist blood pressure and they are large and inaccurate
Score: 6 Votes (Like | Disagree)