Yes, your Apple Watch can alert you to abnormal heart rates, including high/low rates while inactive and irregular rhythms suggestive of atrial fibrillation (AFib), by sending notifications you can customize in the Watch app on your iPhone. It uses built-in electrodes and optical sensors to check your heart's activity and can alert you if your heart rate exceeds or drops below set beats per minute (BPM) or detects irregular patterns.
The irregular rhythm notification feature on your Apple Watch will occasionally look at your heartbeat to check for an irregular rhythm that may be AFib. This usually happens when you're still to ensure a more accurate reading.
Your Apple Watch can tune in to your heart and send notifications when something out of the ordinary occurs. For example, your Apple Watch can notify you if your heart rate remains above a chosen threshold or below a chosen threshold after you've been inactive for at least 10 minutes.
Get heart health notifications
You can enable notifications from the Heart Rate app on your Apple Watch to alert you to high or low heart rates, as well as irregular heart rhythms that may be suggestive of atrial fibrillation (AFib).
No, Apple Watch cannot detect heart attacks. It can only detect irregular heart rhythms, which are a risk factor for stroke. If you ever experience chest pain, pressure, tightness, or what you think is a heart attack, call emergency services using your iPhone or Apple Watch manually and immediately.
Cardiologists have mixed views: they see the Apple Watch as a useful tool for increasing heart health awareness and monitoring known conditions (like AFib) when used with a doctor, but many caution against using it for self-screening in healthy people due to high false positives and anxiety, emphasizing it's not a replacement for clinical devices or physician expertise. The American College of Cardiology (ACC) offers guidance, suggesting it's best for general wellness or managing existing issues, not primary screening, and continuous monitors are better for urgent needs.
Knowing you have heart problems involves recognizing symptoms like chest pain/pressure, shortness of breath, fatigue, dizziness, palpitations, and pain in your arms, back, neck, or jaw, which signal potential issues like a heart attack or heart failure, but also less obvious signs like swelling, sweating, nausea, or indigestion, requiring immediate medical attention for sudden or worsening symptoms. Don't ignore symptoms, especially if they're new or severe, and see a doctor for persistent issues like swollen ankles or leg pain during walking.
Some people will even briefly dip below 50 beats per minute. If your heart rate drops under 40 while you're asleep, it may not be a problem — especially if it doesn't do this while you're awake during the day. But it's still a good idea to see a healthcare professional.
Accuracy of Apple Watch heart rate monitor in various settings, for foreground readings. Source: 2024 Apple study. While sedentary, Apple Watch's heart rate monitor is accurate to within 5bpm about 98% of the time. During exercise, about 87% of measurements are within 5bpm and 95% are within 10bpm of the ground truth.
For example, a 10- to 15-minute brisk walk typically elevates the heart rate to 110 to 120 beats per minute. Also, the sinus node increases the heart rate when the body is stressed because of illness. In all of these circumstances, the heart rate increase is a normal response.
Movement and exercise intensity can also throw off accuracy.
You might notice your watch lags behind when your heart rate spikes, or sometimes gives an implausibly high or low number during exercise.
Can the Apple Watch call 911 if my heart stops? While the Apple Watch doesn't automatically call 911, RscMe can alert your chosen contacts if your heart rate is dangerously high or low, who can then act quickly to assist.
Frequent ectopic beats may indicate an underlying heart issue and should be evaluated by your healthcare provider. Smartwatches like Apple Watch, Fitbit, and Samsung watches can help monitor and visualize ectopic beats. This articles provides visual examples of irregular heartbeats on watch ECGs.
If your Apple Watch ECG app shows "Low Heart Rate" for a heart rate between 40 bpm and 50 bpm, there's usually no cause for concern. However, a Low Heart Rate ECG on your Apple Watch may indicate that not enough blood is being pumped out to the rest of your body, which could be a sign of: Sinus Bradycardia.
The pooled sensitivity and specificity of Apple Watch ECG for detecting AF were 94.8% (95% CI: 91.7% to 96.8%) and 95% (95% CI: 88.6% to 97.8%), respectively.
Should I worry about an irregular heart rhythm? Most of the time, an irregular heartbeat goes back to normal quickly and isn't a sign of a dangerous condition. But some types of irregular heartbeats happen because of serious conditions that can be life-threatening.
Cardiologists have mixed views: they see the Apple Watch as a useful tool for increasing heart health awareness and monitoring known conditions (like AFib) when used with a doctor, but many caution against using it for self-screening in healthy people due to high false positives and anxiety, emphasizing it's not a replacement for clinical devices or physician expertise. The American College of Cardiology (ACC) offers guidance, suggesting it's best for general wellness or managing existing issues, not primary screening, and continuous monitors are better for urgent needs.
When you've had a scare or are very emotional or anxious, or are exercising, your heart may send signals more frequently for a short time. This is called sinus tachycardia and goes away when you calm down or rest. You may also have a fast heart rate from substance or tobacco use or from too much caffeine or alcohol.
The maximum rate is based on your age, as subtracted from 220. So for a 50-year-old, maximum heart rate is 220 minus 50, or 170 beats per minute. At a 50 percent exertion level, your target would be 50 percent of that maximum, or 85 beats per minute.
If your heart rate drops into the 30s, that's getting into dangerous territory. You might not get enough oxygen to your brain. This can cause fainting, lightheadedness and shortness of breath. Seek medical attention right away.
A sleeping heart rate below 40 beats per minute (bpm) is generally considered too low, especially if it causes symptoms like dizziness, fatigue, or shortness of breath.
Conditions when the heartbeat goes beyond 120-140 beats per minute or falls below 60 beats per minute, can be considered dangerous, and immediate doctor's intervention is a must.
Nail changes can show signs of heart problems. It's important to watch for these signs to keep your heart healthy. This helps catch heart issues early. Look out for nail changes like clubbing, splinter hemorrhages, and cyanotic nail beds.
Chest discomfort or pain that lasts more than 15 minutes and does not improve with nitroglycerin or rest. It is important to monitor your weight. Weight gain is the first sign that your heart failure may be getting worse. Patients can gain up to 10 pounds of “extra” weight from fluid before feeling bad or swelling.
High cholesterol often has no symptoms, but when it causes problems, warning signs include chest pain, shortness of breath, numbness or coldness in limbs, unexplained fatigue, dizziness, headaches, leg pain/cramps, yellowish skin deposits (xanthomas), a grey ring around the iris (corneal arcus), and slow-healing sores/ulcers on feet, indicating poor circulation. These signs often point to related conditions like Peripheral Artery Disease (PAD) or heart issues from plaque buildup, but the only sure way to know is a blood test.