If you have an Apple Watch, its heart rate sensor measures your pulse every five minutes. That data, stored in the Health app, is a vantage point into understanding just about everything in your life: your sleep, cardiovascular health, stress, and the effect of new habits like exercise.

Download Cardiogram for your Apple Watch here: https://itunes.apple.com/us/app/cardiogram/id1000017994?ls=1&mt=8 We’re also compatible with Fitbit, Garmin, or WearOS by Google.

Third party apps like Cardiogram for Apple Watch can help you understand what your heart is telling you. Here are five patterns we’ve learned from analyzing more than 10 billion heart rate and exercise measurements from Apple Watch as part of our research to detect health conditions with wearable sensors.

1. Your Sleep Quality

Do you ever struggle to get to sleep? Your heart rate data can give you clues on how long it takes you to fall asleep and whether the sleep you’re getting is restful. For instance, here’s my colleague Johnson’s heart rate during one night of sleep:

The blue lines are below 60 bpm, and the yellow lines 60 bpm and above. Based on the color, you can see it took him about a half an hour to reach deep sleep. Don’t worry if you see spikes every 90 minutes — those are your REM cycles and they’re normal.

2. Resting BPM

Your heart rate at rest — awake, but not moving — is a key indicator of your overall health. Most people are between 60 and 100 bpm, lower is usually better, and for every 9 bpm you lower your resting heart rate, your chance of death goes down by 10%.

Resting heart rate is a key metric of cardiovascular health. You can trend it over time (left), compare yours to other people (center), or find a new habit to lower your resting heart rate. Screenshots from Cardiogram.

If your resting heart rate is higher than you’d like, exercise can lower it. The Habits tab helps you track whether a given workout routine works for you.

3. Heart rate recovery after exercise

We all know that when you exercise, your heart should be pumping. But what happens in the minutes afterward can be even more important. Doctors define heart rate recovery as how quickly your heart rate drops two minutes after exercise. For example, if your heart rate while walking is 120 bpm, and two minutes after you stop walking it’s 80 bpm, then your heart rate recovery is 35 bpm.

Heart rate recovery is a metric of cardiovascular health, measured after a workout.

4. Stress and Calm

Stress is the leading cause of spikes in heart rate among Cardiogram users.

When you feel stressed, your veins constrict and your heart races — and if you have an Apple Watch, you might get a notification to breath deeply. When your heart rate spikes, we ask you why (left), and by far the most popular response — people have recorded 20,000 moments of stress through Cardiogram. To take care of stress, use the breath app, exercise, or meditate.

5. In the future: medical conditions

People are already discovering medical conditions, like abnormal heart rhythms through their Apple Watch. App developers and medical researchers are collaborating to make early detection of medical conditions an everyday reality rather than a one-time miracle. For example, in December 2016, Stanford published early results on one of the first ResearchKit studies. Likewise, we presented preliminary results on our study with UCSF Cardiology at a workshop in a top artificial intelligence conference.

In 2017, as the research matures, you’ll results showing how everything from sleep apnea to diabetes to abnormal heart rhythms can be detected using wearable sensors. And, perhaps one day in the far future, rather than getting a blood test at the doctor, they’ll just scan your watch instead:

Wouldn’t that be great? If you want to contribute, you can sign up to participate in our study with UCSF Cardiology here.

Bonus: Your heart rate during Rogue One

People have recorded their heart rate during Game of Thrones, horror movies, and more. If you see Rogue One, try turning on continuous recording mode and see which scene got your heart pumping the most.

Download link: Cardiogram for Apple Watch on the App Store.