Let’s talk about measuring blood sugar! What does this mean, really? At some point, probably most of us have had at least one interaction with a glucometer (the little device that has a super sharp needle on it that can read your blood sugar). You prick your finger, put a drop or two of blood on the reader strip, and a number pops up on the screen. But, do you even know what it means?
In the United States, we are reading that number as milligrams per deciliter, or mg/dL for short. In other countries, the number is read as millimoles per liter, or mmol/L (put THAT in your Funk and Wagnall!). The glucometer is checking how many milligrams of sugar are in one deciliter of blood.
The ideal range for a healthy individual is between 80-100 mg/dL. This is would be for a fasting blood sugar (or glucose) level, or 2-12 hours after eating. If we go much more than about 12 hours without eating, blood glucose levels will start to drop below healthy range (below 80 mg/dL). When we eat, our blood glucose levels naturally rise due to the intake and digestion of carbohydrates, fats, and even proteins. About 1-2 hours after eating (or postprandial), blood sugar levels should drop to 120 mg/dL or lower. After 2 or more hours postprandial, blood glucose levels should be back down below 100 mg/dL.
Hypoglycemia occurs when blood glucose levels are too regularly below 80 mg/dL. This can happen for a couple of reasons. You may have gone much too long in between eating, or you may have eaten something very high in sugar, experienced a sugar “high”, and then crashed within about a half hour afterwards. Symptoms of hypoglycemia (hypo- meaning low, glycemia- meaning sugar) include mood swings (generally irritability), shakiness, brain fog, and/or fatigue. The brain needs a constant flow of glucose in order to function. In extreme cases, once it has gone through all of its glucose stores, it will start breaking down proteins (muscle tissue) in order to get the glucose it needs. Too much protein in the blood stream will cause the blood to become too acidic (ketoacidosis, not to be confused with ketosis). It can be deadly to have your blood sugar levels go too low.
Generally what do you do when your blood sugar gets too low? You eat, and more often than not, you eat really sugary foods to jump your blood sugar levels up quickly. Around and around this cycle of sugar lows, eating, then sugar highs continue. Insulin (the hormone secreted by the pancreas to try and lower blood sugars) is “running” all around the body trying to regulate the blood sugar levels. If hypoglycemia goes on too often, the body will start to become resistant to insulin. OK, wait, stop! What? Insulin? What is that, you ask? We haven’t gone into the digestion part of blood sugar, that’s in another post. So, you just have to hold on and go with me. Insulin Resistance occurs when blood glucose levels hang out too often between 90-120 mg/dL (averaging around 100 mg/dL), even after fasting. This is not a good place to be in either. Essentially, there is too much sugar in the blood, and too much of the hormone insulin in the blood. The cells in the body that accept insulin start getting really tired of constantly being bombarded by insulin and sugar, and start to shut down. Not good at all!
The next step, since the cells aren’t capable of accepting insulin and sugar, sugars that come through the blood stream pretty much just stay there. This keeps the fasting blood glucose levels regularly above 100 mg/dL, called hyperglycemia. Hyper- meaning high, and glycemia- again, meaning sugar, is just as bad as hypoglycemia (although its effects aren’t nearly as rapid as hypoglycemia). If a person has been diagnosed as “pre-diabetic”, (s)he is hyperglycemic, and well on the road to Diabetes if (s)he doesn’t make some serious lifestyle changes.
The final step of this blood sugar roller coaster is Diabetes. This diagnosis comes when the blood glucose levels are regularly above 200 mg/dL. Sugar is running rampant in the body, and the insulin isn’t doing anything anymore. There are two different types of Diabetes. The cascade of events that have been describe above is in reference to Type 2 Diabetes. Type 1 Diabetes is an autoimmune disease in which the person’s pancreas just doesn’t work at all from the get-go (check out this post about how blood sugar is actually digested to get more info!). A person with T1 Diabetes can still go through the cascade of events, but will happen much faster if not properly regulated with insulin injections.