Introduction
I’m sure it’s already happened to you too… A moment of fainting, a feeling of imminent fainting or in any case of sudden malaise… Low sugar, right? And so here’s a nice bag of sugar and everything passes… but what if I told you that the explanation was probably something completely different?
Let’s take a step back for an important premise: our brain, through specific hormones, takes care of maintaining the amount of sugar in the blood in a well-defined range of values:
- not too low, because otherwise the cells that need it immediately may not find it,
- not too high, because otherwise it would wreak havoc around the body.
These disasters are the potential complications of diabetes, a disease that can manifest itself in many forms, but all have in common the inability to maintain normal circulating sugar levels, levels which instead tend to rise too much.
The so-called drop in sugars is instead the opposite condition, i.e. an insufficient quantity of sugar in circulation, in particular less than 55 mg/dL (slightly more or less depending on the sources consulted and the type of person referred to) and the medical name is hypoglycemia.
Hypoglycemia is frequently observed in patients with diabetes mellitus, especially in those who use insulin, but is instead very rare in non-diabetic patients, although possible, especially in healthy subjects who do not present specific risk factors which we will see shortly.
This article, unless otherwise indicated, will therefore referred to NON-diabetic patientsto understand when a drop in sugar can actually occur and what instead can cause the symptoms that come too quickly associated with this condition much more frequently.
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Symptoms
Let’s start with the symptoms of hypoglycemia: we said it is defined as a blood sugar value lower than 55 mg/dL, but it is important to note that the disturbances can also be perceived with higher values (less than 70 mg/dL) or even all numerically normal in the event that a rapid drop in blood sugar has occurred.
The disturbances that occur in the event of a drop in sugar can be didactically distinguished as mild, moderate or severe based on the blood sugar level reached:
- When blood sugar drops below 70 mg/dL they can appear
- Fame
- Nervousness and tremors
- Increased sweating
- If the values fall further, below 55 mg/dL, the patient may develop:
- If it drops further below 35-40 mg/dL, the condition becomes life-threatening, with the possible development of
However, an important clarification is necessary: you must not think that up to 55 mg/dL only hunger, tremors and sweating are caused and then, as soon as the value drops to 54, the others appear. Instead, they should be understood as a spectrum of possible disorders of increasing severity, which appear in a sort of continuum not only as we said before based on the speed of descent of the values, but also based on one’s state of health. For example, at the last check I did, I found a value of 60 and something, but I was fine and it’s probably therefore a physiological value for me.
However, let’s limit ourselves to the three less serious symptoms:
- Fame
- Nervousness and tremors
- Increased sweating
Already from these it should begin to be clear that what we call “low sugar” probably has different causes, because we bring it up when we feel a sudden sense of faintness, perhaps of slightly blurred vision. What could it be? I’ll tell you shortly, but let’s close the glycemia circle by going to see when it could actually occur in non-diabetic subjects.
Hypoglycemia in NON-diabetic subjects
Having clarified that an effective drop in sugar in non-diabetic subjects is rare, this can still occur and from a medical point of view, two cases can be distinguished:
Reactive, or postprandial, hypoglycemia occurs with a full belly, after eating, typically when a lot of carbohydrates are consumed. In particular, pre-diabetic patients, or perhaps with specific risk factors, could have difficulty in correctly managing these carbohydrates introduced, which are nothing more than sugars, and could therefore trigger phenomena of sudden increase in blood sugar followed quickly and abruptly by equally rapid declines, confirming the metabolic difficulties.
But these are precisely, at least in most cases, subjects with specific risk factors, which also include conditions such as stomach surgery or rare metabolic diseases.
The second case instead foresees a possible fasting hypoglycemia, but even in this case it is generally diagnosed in patients with obvious risk factors, such as:
- in therapy with some drugs that could favor its development, among which the most common is aspirin, but there are so many others,
- alcohol, especially in the case of binge-drinking, or exaggerate badbut only occasionally
- nervous anorexia,
- very serious diseases affecting the liver, heart or kidneys,
- severe hormonal changes, such as cortisol, growth hormone, glucagon, thyroid hormones or adrenaline,
- or still relatively rare tumors, such as insulinoma.
In short, as you will have understood, a drop in sugar is possible in a non-diabetic patient, but it doesn’t really seem to be a compatible explanation for all the times we bring it up.
Because if the symptoms go away with sugar it is not a confirmation
Is there a way to tell if the cause is sugar? Obviously yes, and three conditions must be met:
- Symptoms compatible with a picture of hypoglycemia.
- The symptoms should disappear with the intake of sugar.
Alt… I know what you’re thinking… my symptoms are compatible and above all everything always passes with sugar, so in my case it is. No, that’s not enough, the third condition is to verify that the values were actually lower than normal. This is essential, because otherwise what you can say is that the disturbances have passed AFTER the intake of sugar, but you are not sure that they have passed THANKS to the sugar.
It is a subtle but fundamental difference. A temporal correlation “I did A and it happened B” never allows us to say “A causes B”.
Then what can it be?
What we refer to as a drop in sugar in most cases is a drop in blood pressure, a hypothesis which is confirmed by the fact that one often feels better in a lying position, while hypoglycemia would actually require the introduction of sugar.
If the pressure suddenly decreases, the blood flow to the brain is reduced and is felt instantly
- sense of faintness, up to a real syncope in the most severe cases
- light-headedness
- dizziness
- blurred vision
- muffled ears
and it is quite spontaneous to assume the lying position, thus restoring cerebral perfusion and avoiding fainting.
It is not necessary to go into detail about all the possible causes, but it is perhaps worth highlighting some rather common cases:
- differently young subjects, perhaps taking drugs against high blood pressure, could be subject to sudden drops in blood pressure by getting up too quickly, i.e. developing an episode of so-called orthostatic hypotension,
- but even more simply to remain still and standing for long periods, with the blood tending to collect in the legs,
- too hot environments or summer season, because the heat tends to induce vasodilation (the blood vessels tend to relax and the pressure drops),
- dehydration, when you drink too little,
- after physical activity, especially in hot conditions and without adequate introduction of liquids and mineral salts.
What to do in these cases?
If in the mildest cases it is often sufficient to sit down and wait a few seconds for the brain to take control of the situation by correcting the pressure, in more severe cases it may be necessary to lie down and perhaps raise the legs, a position which favors the return of venous blood towards the heart and then on to the brain.
Obviously not sugar, because it would be useless, but a nice large glass of water, even two. Alcohol is also prohibited, which would make the situation worse.
Finally, I recommend that you report any abnormal episodes to your doctor: it is clear that if it happens once in your life after running a marathon at an ambient temperature of 30° the cause would be quite evident, but in the presence of unclear conditions, or moreover, if the episodes were repeated, it would become absolutely essential to investigate and understand the causes, whether it be blood sugar, blood pressure or something else.