Glucose is essential to our body and its healthy functioning as it is responsible for supplying energy to the different organs in the body to perform various vital functions. Glucose levels oscillate throughout the day, which is quite usual unless the levels either go very low or too high. Unsteady glucose levels are usually associated with metabolic dysfunction and other medical complications like obesity, diabetes, cardiovascular complications, hypertension etc. 

Monitoring the glucose levels in our blood is the first step toward building a healthy glucose metabolism. However, we can only manage something that we can measure. Therefore, continuously tracking our glucose levels using devices like Continuous Glucose Monitor by HealthifyMe is the answer to making informed choices for long-term health.

Glucose Monitoring shows you how your body relates to food and how it can put your glucose levels haywire. As a result, you automatically learn to reduce or eliminate the intake of certain foods. But the good part is that you develop healthier long-term food behaviour and build a healthy glucose metabolism, saving you from several health issues. But what type of glucose monitoring technique you should adopt can be confusing. Many studies talk about the best approach.

What is Interstitial Fluid, and What Role does it Play in Glucose Monitoring? 

We know that the sensors attached to the Continuous Glucose Monitor measure the blood glucose levels from the interstitial fluid. But what are they? Interstitial fluid is the liquid that fills the space between the cells in our body. This fluid contains water, fatty acids, sugars, amino acids, hormones, coenzymes, salts, neurotransmitters and cellular products. When the fluid 

gets over, it gets replaced by new fluid. The old and used fluid is drained to the lymph vessels and continues their function. The tissue fluid is called lymph. 

These fluids surround and bathe every cell present in the body, and it is their function to bring oxygen and other nutrients to the different parts of the body. They also help remove waste products that form as byproducts in any part of the body. Interstitial fluid is similar to blood plasma as they continuously exchange substances across capillary walls. The main difference between the two is that blood plasma gets contained inside the blood vessels, but interstitial fluid is everywhere around the body. 

As mentioned above, the interstitial fluid is the fluid between the blood vessels and the body’s cells. The fluid is responsible for transporting oxygen, nutrients and glucose to all the cells in the body.

Glucose uses a concentration gradient as its transport to move freely and directly into the interstitial fluid from our blood. This movement from the blood to the fluid is influenced by factors such as insulin sufficiency and the metabolic rate of the surrounding cells. Once glucose enters different cells in the body through the interstitial fluid, it gets trapped there, and it will not be able to return to the fluid or the bloodstream from there.

Glucose Monitoring Through Interstitial Fluid

The reasonably new glucose measuring device called Continous Glucose Monitor or CGM measures your glucose levels through your interstitial fluid, and studies have found this method to be quite effective. These devices, especially those developed by India’s top digital health platform, HealthifyMe, measure our blood glucose levels 24/7. Moreover, they let you know the measurements whenever you want and immediately alert you if your blood glucose level is too high or low.

CGMs measure glucose levels in our blood through interstitial fluid, unlike other measuring devices that use blood for measurements. The former is hassle-free compared to the latter, as you needn’t pinprick your arms or fingers often to get results. In addition, measurement through interstitial fluid also helps you understand a trend that may spike blood glucose levels. 

When glucose levels are measured using blood tests, glucometers, etc., the result is instantaneous. However, the levels may vary depending on whether you had a meal sometime before or similar factors. Since these tests are also one time, you may not be able to know what resulted in your unbalanced glucose levels. So making any changes to your diet plan or taking medications following such blood glucose tests may not give you data points unless you repeat a test. 

Using CGMs that continuously measure your glucose levels through interstitial fluids is an ongoing process. You get to record your glucose levels on a real-time basis. Therefore, you will be able to figure out the behavioural patterns you must fix. As a result, you make informed dietary choices that you must incorporate or the lifestyle changes you must adopt. This assures that your body has a healthy glucose metabolism. 

Sometimes, CGMs may slightly delay providing the readings, especially after eating or exercising. Health coaches often refer to this delay as time lags. It is simply a period taken by the glucose to move from our bloodstream to the interstitial fluid. This time lag can range anywhere from five to twenty-five minutes. 

What is Blood Glucose, and What Role does it Play in Glucose Monitoring?

Blood glucose, or blood sugar, is the main glucose in our body. It comes from the food we consume and is the primary source of energy in our bodies. With the help of interstitial fluid, the bloodstream carries the glucose to different parts of the body to provide energy to all the organs and cells. Glucose performs vital functions important for our sustenance.

The main difference between blood glucose and the glucose in interstitial fluids is that the former carries the glucose to different body parts. On the other hand, the latter is responsible for transporting glucose to all the cells.

Glucose Monitoring Through Blood Glucose

The blood glucose level or glucose concentration that we get on measuring is a marker of the total available glucose at the time of the test. However, this concentration fluctuates throughout the day, especially after eating a meal or exercising.

Studies note even around a 20 mg/dl difference between arterial and venous blood glucose levels. Therefore, the blood glucose measurements that we take using a fingerpick correlate to the arterial blood glucose levels.

However, there may be variables due to blood flow mobility. Hence, the blood glucose levels may be different at different sites. Specifically, the blood glucose level measured from the forearm will be lower than that calculated from the fingertip at times. This is due to rapid increase and higher at times of rapid decrease in systemic blood.

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Interstitial Fluid Glucose Monitoring Vs. Blood Glucose Monitoring: Basic Differences

Both blood glucose monitors and interstitial fluid glucose monitors or continuous glucose monitors can often show similar measurements. Nevertheless, the readings can differ between the two after or during meals or exercises. Also, this is because the latter may undergo a time lag while this is absent in the former.

However, regular CGM users, health coaches and diabetologists say that such differences are short-lived. Furthermore, they are not big enough to be seen as a hindrance or limitation of this monitoring system.

Another notable difference between the two systems is that one is easier to use and measure while the other may be a bit of a hassle. Continuous Glucose Monitors can be easily attached to our arms or belly, and we don’t have to bother about it further. Whenever we want or need to know our glucose levels, all we have to do is to check our mobile devices or trackers wirelessly connected to the CGM sensor.

However, Blood Glucose Monitors require us to prick our skin often to collect blood samples to help conduct the test. So, this technique is not easy to use very often as we may not prefer pricking ourselves often, and besides, the number of test kits available might not suffice for knowing the desired results.

Older studies note that Glucose monitoring through blood glucose may be a better option as the same is more accessible than interstitial fluid. But the case is not the same anymore since the invention of the Continous Glucose Monitor.

These devices that are part of the new HealthifyPro 2.0 package are significantly more convenient than blood glucose monitors. They also come with additional perks like a personal health coach and an AI. As a result, the users receive personalised care and advice to improve their glucose metabolism. Also in turn, it helps them lead healthier lives.


Blood glucose and interstitial fluid glucose levels can fluctuate throughout the day based on food, medications, stress and the amount of exercise we do. Therefore, everyone must keep track of their glucose levels, irrespective of diabetes or no diabetes.

Glucose Monitoring happens either through interstitial fluid or blood glucose, depending on your convenience and choice, but you must regularly keep track of your glucose metabolism.

Devices like glucose metres are the ones that measure blood glucose to get the readings of the glucose level in our body. These devices use pinprick testing to get the required blood needed to get the reading. On the other hand, a Continuous Glucose Monitor is a device that measures glucose levels through interstitial fluid, and it keeps track of our glucose metabolism at all times.

One of the best CGMs available now is undoubtedly that of HealthifyMe. The HealthifyPro provides expert guidance that we can truly rely upon to improve our health and fitness outcomes.