How fast is fast?

roller-coaster-365770_640Have you ever felt a little low, only to check your blood sugar and it is Ok?

I have always thought that this was due to a rapid drop in blood sugar levels. But that started me thinking – exactly how fast is fast? In other words, at what rate must BG levels drop in order to start feeling this way?

Is this feeling really due to a rapid drop in BG’s? Or could it be something else, perhaps some intricate balance between blood sugar levels and insulin levels? The body is an amazing “machine” and the mechanisms that manage a non-diabetics blood sugars is astounding. Maybe there’s more to it than just the dropping BG.

What do you do when you feel this way?

I’m at 142 about 2.5 hours post meal. That’s good. But I feel “funny”, like I’m low. But the symptoms are so very slight. 8 minutes later I do another test. 137. Is it really going down, or could that difference just be the variance you will find in any two tests. If it is really going down, how far will it go?

Well, this all depends on how much of that last bolus is still working to lower the blood sugar. I have my insulin duration set to what many people will think is too long. I’ve got it set to 5:30. Yes, that’s right. 5 hours and 30 minutes. I don’t want to go too off-topic on this post, so maybe I’ll address that subject at another time in another post.

3 hours post meal and I’m at 127. Still the tail of a little less than 3 units on board. However I know that it’s mostly the “tail” of that insulin, which has much less of an impact on my blood sugar.

Still feeling a little off, but I notice that it’s subsiding a bit. Or maybe I’m just getting used to it? Time will tell.

A point I want to stress is that I am in a situation where I can keep a very close eye on things. If the scenario were a bit different I may choose to just pop a couple of glucose tabs and be 100% sure that I won’t go low.

4 hours post meal and I’m at 91. It would be good if the BG descent stops here.

4.5 hours post meal and I’m at 74 with 1.07 units of residual lunch bolus (almost all “tail” though).

At this point I’m ending the experiment and having 4 glucose tabs. I’m not comfortable being in the 70’s, and I also need to walk up to the service station to pick up my beat up old truck, so I need a little boost for that walk.

But why did I start feeling off with a blood sugar of 142? That is the point. There must be more to the equation than just hitting a key number that kicks off the symptoms of low blood sugar, however slight those symptoms might be.

To summarize my BG’s all in one easy to read place:

1:48 – 142 – started feeling slight symptoms of low BG.
1:56 – 137
2:30 – 127
3:30 – 91
4:00 – 74 – end of test – ate glucose tabs.

Is the drop I experienced this afternoon fast enough to be considered “rapid”, and could it be that “rapid” change that made my experience the symptoms? But I’ve had one other experience that might indicate it’s not the rapid changes? Was it a fluke? Who knows. That experience is an interesting one, and you can read about it here.

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13 thoughts on “How fast is fast?

  1. Fear of hypoglycaemia is the real killer of diabetics, a post meal blood sugar of 142 is not normal in a non diabetic therefore puts you at risk of complications. The only way to remain healthy with diabetes is to maintain stable bloods under 120 and yes that does mean putting yourself more at risk of hypoglycaemia but it won’t kill you, been doing it for 3 years now and at one point I was having 30 lows per week and guess what I’m still here alive and healthy with a hba1c of 4.9% or 30.

  2. I do not have diabetes but frequent episodes of hypoglycemia. I think the drop doesn’t sound too fast. I know when I feel weird despite a normal BG it drops much quicker but it may just be me. For example, just a few minutes ago mine dropped 10 points in 13 minutes.

  3. My levels drop fast. For example, I haven’t been feeling good all day. My fasting level was 101. Not bad. I had lunch around 12:30 and tested a hour later (research told me to test an hour after I started eating), level was 148. At 4:36, I tested again. Level dropped to 86. Two hours later, after a grilled cheese, it was 96. Now I admit, I’m still learning how to do this, but a drop of 62 points (?) doesn’t seem normal to me. When it drops like that, I feel it…headache, nausea, fatigue…like today.

  4. This is a very old post, but the speed at which my blood sugar drops is a huge factor in how noticeable it is to me. Fast drops are very problematic because sometimes I can’t catch them before I pass out – for me a quick drop would be like one time I tested about an hour or so after having a protein bar at 12:15 and was at 165…. At 12:45 I came to on the office floor with EMTs there and was at 50…. Not sure what it dropped down to… Those are the ones I hate, when it is like to cord broke on my blood sugar elevator and I crash to the ground…

  5. This is such an old post, but I’m going to reply anyway. I’m new to your blog and have a way you can check. When I was pregnant, my nurse told me that they would rather I checked BG on my fingertip as opposed to my forearm, which I usually use. She said that, due to circulation differences, my arm would show my BG from about 1/2 hour ago, and my fingertip would show almost instantaneous results. Since then, when I feel weird and it’s not supported by my reading, I check both and get a good indicator of direction. So if I feel low and my arm says 150, but my fingertip says 95, it’s dropping fast. Same the other way. Not sure if you always use fingers, but may help others.

  6. I know what you are talking about. And yes, I agree you can feel the rapid change whether or not it drops into a dangerous level.

    Here is an article with references that states that when testing for hypoglycemia that it is the suddenness of the drop, not the level of the depth that causes the symptoms.

    Don’t know much about the author, but it appears to be well documented.

    Cheers and good luck.

  7. Allison, your calculation is a bit incorrect. He dropped 68 pts in just over 2 hours. His 142 was at 2.5 hrs post meal and his 74 was around 4.5 hours post meal. That’s only a 2 hour difference. While 70 pts isn’t terribly drastic over 2 hours, it does indicate a continuous downward trend that Scott picked up on correctly.

    – Jeff

  8. When I drop quickly I feel low at much higher levels that I normally would. Last week once I felt low, tested, was 75, which isn’t low enough for me to want to treat, took out garbage, came back in, and was feeling even more low, I clocked in at 60 then. I usually feel fine at 60, but fast drop has a lot to do with it. This is actully called “relative hypoglycemia.”

  9. Allison – That is a good point. I don’t remember what my pre-meal BG was that day. It could have very well been high.

    Johnboy – Each day is it’s own day, but I’m afraid to say that my overall average is close to 200!! A lot of that is due to eating too soon after my last meal – it’s like I’m not even giving my BG a chance to get back down before I’m back at the fork & spoon again. So that too might account for the strange feelings.

  10. I concur. It doesn’t seem fast enough, and these readings all look A-O-K to me!!

    Definately an interesting theory though about feeling low when you really aren’t due to rapid drop.

    Tell me, Scott…are these levels normal or do you typically run a bit higher? I know that the body can feel low if it is used to running at a higher bg most of the time.

    Best wishes!

  11. Well, a BG of 142 isn’t even close to being low (which is normally <70), so I'm not really sure if that "funny feeling" was because your blood sugar had dropped post meal, or if it was, well, just you. You also didn't mention what your blood sugar was pre-meal. If you had been 300 pre-meal, and were 142, post-meal, I could totally see you feeling low, because you had such a huge drop. Your body was probably going "woah, what's going on?"

    But if you were around 150, then it wasn’t much of a drop. And it took your body 4.5 hours to go from 142 to an actual low, which is a long time, so I’m not sure if your body would have been *that* in tune with the fact your blood sugar was dropping.

    Ok, so basically, in my totally, completely, 100%-not-professional opinion is: no, it wasn’t a rapid enough drop to constitute feeling low (unless of course, you started the entire scenerio at 300, which you don’t mention), but yes, you can feel a low when you’re not really low if you plummet fast or if you plummet a lot. I catch lows in the 80s because I can feel my body dropping. It’s not a strange thing, it’s just most people aren’t that aware.