To understand Hypoglycemia, we first have to understand "normal" blood sugar control. And by normal, I mean you don't have metabolic syndrome issues. You have good glucose tolerance, and are not yet insulin resistant.
The body loves homeostasis, (balance), so it does whatever it has to, to keep your blood sugar level within a very tight framework. In other words, normal blood sugar doesn't bounce all over the place. There's a very specific curve or path that it follows.
Normal blood sugar runs around 80 mg/dl, which is where one's "fasting blood sugar level" or "baseline" should optimally be. Until you eat something, and then it's goes UP. In a healthy individual, this blood sugar rise never goes above 120 mg/dl, irregardless of what or how much you eat.
Now, when blood sugar rises, first phase insulin is dumped into the bloodstream to help shuttle the glucose into the cells. The amount of insulin dumped is generally dependent upon what you ate the LAST TIME. Not what you're eating right now. If that's enough, great. Blood sugar level will slowly return to normal, and your cells will be well fed. If it isn't enough, the body will produce more insulin which keeps trickling into the bloodstream until it is.
The amount of time this takes obviously depends on what you ate, and how much. But generally speaking, after a typical meal, it takes 3 hours for the blood sugar to return to a normal baseline level. After which it pretty much stays there, irregardless of how long you go without eating. Thanx to Glyconeogenesis.
There are three types of Hypoglycemia. Drug induced, Reactive, and Fasting.
Drug induced hypoglycemia is pretty self explanatory. You take too much insulin, you take too much Metformin, or some other type of drug that interfers with the above process.
Reactive Hypoglycemia is when you produce too much insulin. The spike causing the blood glucose level to either go below baseline, or to fall too quickly. This occurs within 5 hours of eating. But generally you hit your lowest level somewhere between 1 and 3 hours. At which time other hormones comes into play to kick the blood sugar back up to normal. Normal meaning baseline.
However, it doesn't work that way with Reactive Hypoglycemia. Usually the hormone kick results in higher than baseline glucose levels somewhere between hours 2 and 3.
Fasting Hypoglycemia is when you're either fasting for longer than 5 hours, or you find yourself in a situation where you can't eat for that long, and as a result, your blood sugar drops below 70 mg/dl.
All three conditions means your body is not reacting normally. Something in the pathway is amiss.
Hypoglycemic symptoms do not come from the level of glucose in the blood. They come from adrenaline which is kicked into gear whenever the blood sugar level begins to fall too quickly, or when glycagon isn't able to convinse the liver to release it's glycogen stores.
So just because you aren't experiencing so-called Hypoglycemic symptoms, (irritability, dizziness, weakness, hunger, craving for something sweet, need for caffeine, etc.), that doesn't mean you aren't having a problem somewhere in the cycle. Because like anything else, it is very easy to get USED to the response to adrenaline your particular body has. Even going so far as becoming "addicted" to the energy rush that adenaline gives you, or mistaking that energetic feeling for a healthy response to whatever you've been eating.
When blood sugar is up, a hypoglycemic is hyperactive, energetic, and feels happy. When the blood sugar starts to drop they feel irritable, tired, and begin craving a quick pick-up. If one uses diet caffeinated drinks or coffee to do that, energy drinks or whatever, the caffeine stimulates the adrenal glands to encourage the liver to release glucose into the bloodstream.
One of the major problems with a Hypoglyemia diagnosis is that there is often a very small window when the blood sugar actually falls to the point where adrenaline is necessary. With that window usually being only about 5 minutes or less. So testing every hour, or even every half hour, can easily miss your lowest point. And make you think you are healthy, when you are not.
Now one of the keys to diagnosis is comparing your blood sugar curve to a normal curve. Because there's some very interesting things that happen when we're caught up in Hypoglycemic cycles. Typical body response to falling glucose levels is to first activate glucagon, which informs the liver that it needs to convert it's glycogen stores into glucose to keep the glucose blood level at baseline.
However, if the liver doesn't have any glycogen stores, or simply doesn't respond to glucagon's signal, maybe can't manufacture glucose through Gluconeogenesis fast enough, the blood sugar level drops to the point to where other hormones rush in to save the day. That's where adrenalin comes in. When the blood sugar drops below 70 mg/dl, a surge of adrenaline is released. But adrenaline always overshoots the mark. So rather than returning the glucose level to baseline, it raises the blood sugar above baseline, and you end up with BOUNCING values.
Most who are officially diagnosed with Hypoglycemia (either Reactive or Fasting) have been known to demonstrate very low glucose levels. Waaay below the 60s that we've been discussing here. Mostly because of the high glucose required for testing. So it isn't just a matter of checking what our blood sugars are doing within a low carb framework. Since low carb is the typical corrective treatment.
Hypoglycemia causes a lot of "fight or flight" symptoms associated with the blood glucose's decline. Then improvement of symptoms upon eating. Getting that pick up. But sometimes this can be caused from the stomach emptying too soon. But most of the time it has to do with a damaged carbohydrate metabolism.
MILD Reactive Hypoglycemia, while not life threatening perhaps, does interfer with weight loss and health. Because whenever blood sugar rises, or is in a bouncing situation, insulin elevates or continues to stay elevated as it's the ONLY hormone that lowers blood sugar, clears the blood of current fatty acids and proteins, and locks up fat stores. Not a good situation to be in if fat loss is your goal. PLus there are loads of health issues that result from elevated insulin, in any degree.
Now there's another form of Hypoglycemia known as Fasting Hypoglycemia. It occurs more than 5 hours after your last meal, and is diagnosed when the blood glucose level drops into the 60s or less. It has many causes: drugs, organ failure, hormonal deficiencies (like adrenal fatigue), non-beta cell tumors, congenital and/or enzematic disorders (hypoglycemia in kids), or elevated insulin levels caused by Insulinoma (tumor of the beta cells), autoimmune situations to either insulin itself, or the insulin receptors. It can also be caused from drinking and eating carbs at the same time, or a damaged liver. So that's another possible dangerous situation to be in, because if the body is reacting normally, it just doesn't happen.
Also keep in mind, that for a glucose tolerance test to be accurate, you have to be eating a diet high in carbs. The purpose being to stimulate the pancreas to its full potential for secreting insulin. Plus home glucose meters are not accurate enough to show you exactly what's going on if you're suffering from more than mild Hypoglycemia. They can be as much as 15% off. They were created for high blood glucose accuracy, and begin to fail somewhere in the 60s.
So if you're having readings that are anywhere near what we been discussing here, go and see your doctor for an accurate testing. Please.