The Ultimate Guide to Health Tracking for Chronic Illnesses

This story is part of Health by the Numbers, CNET's deep dive into how we quantify health.

Fitness trackers and apps have made it easier than ever to keep tabs on your own health at home. For many people, the ability to track detailed health metrics at home may seem like overkill. But if you have a chronic disease or are at high risk of developing one, health tracking is a serious matter. You'll often need to monitor your own metrics at home as a complement to your professional medical care, and feeling empowered to do so correctly can make a world of difference for your physical and mental health. The same is true if you're newly responsible for caring for a loved one.

Figuring out which metrics you need to track, though, can be overwhelming at first – let alone finding the best equipment for accurate results. Here's everything you need to know about which health metrics to track for some of the most common health conditions in the US, including diabetes, asthma, heart disease and more. 

Keep in mind that these tools are most accurate when used under the guidance of a health professional, and no at-home device can replace the advanced equipment at a health care facility.

Blood sugar

Monitoring your blood sugar can be incredibly important if you have diabetes or hypoglycemia, and may also be helpful for those with prediabetes. Depending on your condition and your doctor's advice, you may need to check your blood sugar once a day or even multiple times per day.

The easiest and most affordable way to monitor your blood sugar at home is with a glucose test, which involves a simple finger prick. You can also invest in a continuous glucose monitor for more intensive all-day monitoring without the finger pricks. Your insurance may cover a continuous glucose monitor, depending on the severity of your disease.

Cholesterol

Cholesterol is a key health metric -- too much "bad" cholesterol (or LDL cholesterol) puts you at higher risk for heart disease and stroke. Ideal cholesterol levels vary by age and sex. 

You can measure your cholesterol at home, but it's no substitute for a proper test at the doctor. Many home kits only measure the total amount of cholesterol in your blood, rather than differentiating the bad from the good. Also, following the directions can get tricky without an expert to guide you, which can throw off the results, per Harvard Health.

If you do choose to use a home test, the Mayo Clinic recommends looking for one that's certified by the US Centers for Disease Control and Prevention. And if your results show concerning numbers, go to a professional for a follow-up.

Blood pressure

Blood pressure is one of the first vitals that a nurse measures when you go to the doctor. It's an important health metric in general, but especially for people with hypertension, or high blood pressure, as well as people at high risk for it, according to the American Heart Association. It may also be appropriate for anyone with other heart-related health conditions or pregnancy-induced hypertension and/or preeclampsia.

The AHA recommends an upper arm blood pressure monitor for the highest accuracy; only use a wrist monitor if you can't fit an upper arm cuff. Like other home tests, you'll need to measure properly to get useful results. Learn more about how to take your blood pressure at home.

Heart rhythm and rate

Your heart rate is one of the easiest health metrics to track at home -- you can do it yourself without any equipment by just checking your pulse. But if you have atrial fibrillation or another type of irregular heartbeat, you may need a more robust way of monitoring your heart rate and rhythm. 

That's where home ECG (electrocardiogram) monitors come in. Also called EKG monitors, they measure heart rate and rhythm and display the results on a chart. Personal ECGs aren't quite as accurate as professional ECGs, but they're helpful for getting readings at home that you can then take to a doctor if you notice anything unusual. Look for one that is approved or cleared by the Food and Drug Administration.

Note that some smartwatches have ECG technology, including watches from Apple, Fitbit and other brands. Smartwatches aren't medical devices and shouldn't replace an actual ECG monitor, but this may be a useful feature for some people.

Blood oxygen

Measuring your blood oxygen at home became more popular during the COVID pandemic. When recovering from COVID at home, low blood oxygen (below 90 percent) is one sign that it's time to seek urgent medical care. Blood oxygen can also be a helpful health metric to monitor if you have other lung- or heart-related health concerns.

Blood oxygen is best measured with a pulse oximeter, which you can find at most drug stores or online. Some smartwatches can also measure blood oxygen, though most aren't cleared by the FDA for this purpose. 

Unfortunately, even FDA-approved pulse oximeters aren't perfect. Studies show that they're less accurate on darker skin, leading to potentially missed warning signs. Scientists are still working on solutions to this issue. 

If you have darker skin, it's especially important to take multiple readings throughout the day and watch for any physical symptoms of low oxygen, like shortness of breath, a fast heart rate or a fast breathing rate. 

Lung function

If you have breathing problems or a lung condition, such as chronic obstructive pulmonary disease (COPD) or even asthma, you may benefit from measuring your lung function at home in addition to your doctor's tests in the office.

You can measure your lung function using a peak flow meter, available at most drug stores. Measure and record your highest readings every day for two to three weeks. Your health provider can help you determine what a healthy reading is for you. You can also use a home spirometer to measure lung function.

Weight

Weight is another easy metric to keep track of at home with any standard household scale. Small, day-to-day weight fluctuations (think 5 pounds or so) are common for most people, and can be attributed to the digestive process, hormonal changes and other normal bodily functions. 

But it can be important to weigh yourself regularly if you have certain health conditions, such as heart failure, to track how well your treatment is working and whether your condition is worsening. Unintentional weight loss or gain is also a symptom of a wide range of diseases, and a side effect of some medications. 

Weight tracking can also be risky for some people's mental health. Your doctor can help you determine if monitoring your weight is a good idea.

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.