This is the third in a three-part series on how modern technology can help you be your own doctor. Managing your own health is vitally important — because for nearly all of us, the four major causes of death will be heart disease, cancer, dementia, or diabetes. The good news is that technology can help prevent, or at least delay, the onset of these conditions.

Today’s focus: the smartwatch.

There are several brands available, each with its own advantages, but all share one powerful feature — the ability to track key indicators of your health continuously. Here’s what they measure and why it matters:

  1. Heart rate tracking: Your smartwatch continuously measures your heart rate. During exercise, your heart rate naturally rises — but as your fitness improves, it increases more slowly and recovers more quickly. A lower resting heart rate and efficient heart response are both signs of good cardiovascular conditioning and longevity.
  1. Sleep duration and quality. Smartwatches can estimate how long and how well you sleep. Poor sleep or untreated sleep disorders such as sleep apnea increase your risk of early death, heart disease, and dementia. Tracking your sleep helps identify problems early so they can be addressed before they cause lasting harm.
  1. Heart rate variability (HRV): HRV measures the subtle changes in time between each heartbeat. A higher variability indicates a well-balanced nervous system and strong cardiovascular health. Low HRV is often associated with stress, fatigue, or illness — and improving it through fitness, sleep, and stress management is strongly linked to greater longevity.
  1. Oxygen saturation (SpO₂): This reading reflects how well your lungs and circulatory system deliver oxygen to your tissues. Low oxygen levels can indicate hidden problems such as sleep apnea, chronic lung disease, or heart failure — sometimes before you notice symptoms. Awareness of a low oxygen level can prompt timely medical evaluation and treatment.

Putting it all together

Across this three-part series, we’ve looked at three simple yet powerful tools:

  • Automated blood pressure monitors – for tracking and controlling hypertension.
  • Continuous glucose monitors – for keeping blood sugar within a healthy range.
  • Smartwatches – for monitoring heart fitness, sleep, and oxygen use.

Together, these tools form the foundation of modern self-health monitoring — extending your health span and delaying the arrival of the “four horsemen” of aging, disease, and our eventual death.

As my dear mother used to say,

“Today is the first day of the rest of your life.”

Don’t delay — start tracking, learning, and taking charge of your health today.

Dr. Charlie Barnett is a contributor to KnoxTNToday, where he writes a weekly column, DocTalk, sharing his expertise on health and wellness management.

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