How to Start Tracking Your Health with Wearable Devices

Smartwatches, smart rings, and other consumer wearable devices have become increasingly popular, with nearly one in three Americans using them to track their health or fitness, says a 2023 study from the National Heart, Lung, and Blood Institute. These “wearables” can encourage healthy habits and alert users when something is out of the ordinary.

“Wearables can be very, very useful,” says Jennifer Haythe, MD, a heart disease expert at Columbia. “But they can also create a lot of confusion and anxiety. If we don't understand how to interpret our data, it can get overwhelming.”

Dr. Haythe, along with Columbia cardiothoracic surgeon Isaac George, MD, and electrophysiologist Hirad Yarmohammadi, MD, MPH, explain how wearables work and what to keep in mind before incorporating them into your life.

How do wearable devices work?

Wearables are electronic devices worn on the body that use sensors to collect biological data. When the sensors touch the skin, they continuously detect motion, temperature, light absorption, and electrical signals to measure your vital signs, including:

• Heart rate, rhythm, and blood pressure
• Blood oxygen levels
• Movement
• Body temperature

“Each wearable has different features, but most of them use the same kind of technology to detect these signals,” says Dr. Yarmohammadi. At the same time, additional sensors record time, distance, and elevation. Together, they provide a comprehensive picture of how your body functions at rest and during physical activity.

Real-time readings are shown on the device itself or through a mobile app. Some smartwatches can display notifications when an abnormal reading is detected or remind users to be more physically active. Some advanced devices even allow users to add their own data for more precise tracking. They then use artificial intelligence to learn from your metrics, identify your body’s unique patterns, and translate them into personalized insights about your health.

What can wearables tell me about my health?

With all this data, it can be hard to know what’s relevant. Focus on the insights that are meaningful to you. Depending on the device, this may include information on:

• Sleep duration and quality
• Physical fitness
• Heart health
• Where you are in your menstrual cycle, including predicted windows of fertility
• Stress levels
• How your body is affected by and recovers from acute or chronic illnesses

When Dr. George became sick with COVID-19 early in the pandemic, he used his smartwatch to monitor his oxygen saturation, and heart rate while in isolation. “I noticed some clear trends that have actually helped me understand my body. I got hypertensive (high blood pressure) after COVID, and I was tachycardic (fast heart rate) for months afterward,” he says. “I only realized that because I had my watch on and became aware of my vitals.”

In addition to baseline monitoring, you can use wearables to set and track fitness goals. Many devices allow users to choose targets, such as reaching a certain number of steps per day or number of calories burned during a workout. In general, long-term readings are more important indicators of health than individual moments.

“If you see something persistently abnormal—for example, your heart rate is persistently high—that needs to be addressed,” says Dr. Yarmohammadi. “One episode here and there is not as concerning, but if it’s consistent, you should seek medical evaluation.”

What are some of the downsides of wearables?

For all their capabilities, there is a limit to what wearables can provide. “They can’t diagnose some serious conditions,” says Dr. George, such as a complete heart block, heart attack, or stroke. Furthermore, they occasionally record inaccurate measurements. “Sometimes the recording may show extra signals that can look abnormal even when everything is normal” says Dr. Yarmohammadi.

For some people, using wearables to constantly monitor your health and fitness can lead to anxiety—a phenomenon known as cyberchondria. “There's a point where tracking too much can become harmful if it becomes obsessive,” says Dr. Haythe. It can also cause feelings of depression and guilt if certain goals aren’t met. Protect your mental health by disabling non-critical notifications, limiting how often you check your health data, and consulting your doctor before and while using a wearable.

What should I keep in mind when choosing a wearable?

There are also several practical factors to consider before getting started with wearables:

• Budget: Wearable devices vary greatly in price, ranging from less than $50 to over $500. In addition, some features may only be available through a paid subscription.
• Capabilities: There’s a wide range of what wearables can measure, from basic heart rate to advanced metrics. If you plan on wearing your device in the water, make sure it’s waterproof.
• Comfort: Some smartwatches and fitness rings are large and/or bulky to accommodate screens and sensors, which could make them uncomfortable to wear. Additionally, some devices may not be safe to wear during certain activities, such as contact sports, martial arts, or gymnastics.
• Consistency: To get the most accurate and comprehensive readings, some manufacturers recommend wearing their devices whenever possible, including while sleeping.
• Technological requirements: Most wearables use mobile apps to display data, so smartphones or tablets are generally required for use. Wearables also need to be charged regularly.

Ultimately, wearable devices can offer valuable insights about your health and wellness, but they can’t replace your intuition—or your health care provider’s medical advice. “The goal is not to watch your heart—it’s to live well with it,” says Dr. Haythe. “If you have any questions about your own heart health, your doctor's always your best resource.”

Jennifer Haythe, MD, is the Irene and Sidney B. Silverman Associate Professor of Cardiology, Center for Advanced Cardiac Care at Columbia. She is also the director of Columbia’s Adult Pulmonary Hypertension Program and Cardio-Obstetric Program, and co-director of The Columbia Women’s Heart Center.

Isaac George, MD, is a professor of surgery and medicine at Columbia, the surgical director of Columbia’s Structural Heart and Valve Center, and co-director of the Mitral and Tricuspid Center.

Hirad Yarmohammadi, MD, MPH, is an assistant professor of medicine at Columbia University.