Does anyone else have rebound highs?

I have been having times lately where I will rebound after a sharp drop in BG’s or after maybe dropping a little low (low 80’s or maybe mid 70’s). Without any treatment of the low, I will,rebound to around 200. This is my Dexcom from today. Was running a little high before lunch and did a correction along with my lunchtime bolus. Dropped to 104 and then shot up. Does this happen to anybody else?

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Dave - When I think of a “rebound high,” it’s in terms of a high that looks a lot like the one you show on your Dex screen but one that rebounds from deeper and sustained hypoglycemia levels below 65 mg/dl. Is your Dex tracking your fingersticks well? Did you feel hypo at the just before noon dip? Adrenaline sweating or shakiness? Irritability and sensitivity to light or sounds?

Now I know each of us can vary in our metabolisms. I don’t get counter-regualtory hormone action (release of adrenaline and cortisol) until I drop below 65 mg/dl. And I don’t get a rebound if I can keep that event to under 15-20 minutes or so.

What may have happened to you here could have been a bit of a timing mismatch between your food and insulin. The resultant high could be because your food ultimately got ahead of the insulin.

If your Dexcom was not tracking actual BGs well and your actual blood sugar dropped to the low 50s, let’s say, then it could have been a counter-regulatory bounce. What do you think?

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are you verifying that the Dexcom readings are all accurate?

Hmmm… I definitely get this from exercise-induced lows. Dunno if that’s what you’re dealing with. But I learned a really long time ago when I was on MDI and running as my primary form of exercise that exercise lows are their own thing. I’d come back from my run and fingerstick test in the 60s-70s or below, but I found that if I treated that as a normal hypo I’d end up far too high in the end, whereas if I could just wait out the side effects (“Eat NOOOWWWWWW!!!”) for a while it would come back up to something close to normal in half an hour or so.

My Dexcom is tracking right along with my meter. And this is not the first time this has happened. I wish I could just say I was over treating a low but I know that is not the case. It has me a bit baffled.

The best way to make some reasonable guesses as to the cause is to know a few more details:

  • Are you on a pump or MDI?
  • Did you take your insulin in advance of your lunch? How many minutes before eating?
  • If you’re on a pump, how old is the site? Is it possible that you’ve overused this site and it’s become scarred?
  • Were there any stressful situations before or during this period?
  • Was there any unusual exercise or activity leading up to this time?
  • What did you eat? How many carbs in the meal?
  • Does this meal usually give you post meal BG problems or does it usually behave better?
  • Are you confident that your basal insulin is set well?

There are many reasons this could happen. Sometimes a cause can’t be found and you just have to move on. But since you’ve said this has happened before, it sounds worthwhile to try to figure it out.

I do experience rebound highs, but usually in the morning or late afternoon. If I go low the rebound might take as much as 5 to 6 hours to hit, and no it is not because of over consumption of carbs. Yes, I used to do that. My doc calls them rebound highs and advises not to treat them. I do treat them, yes I know it is against medical advice, but I hate highs more than the lows. I have found, however they act more like a false high, that is they do not stubbornly stay high


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Signed up for an account just to reply to your post that YES, this is exactly what happens to me many nights after eating dinner. It happens more often on a higher carb, higher glycemic index meal (for ex. one w/ bread). I am newly diagnosed so can’t offer much insight as to what’s going on or how to correct. For ex., a few days ago this happened, my glucose went down to 90 after going to 160, I’m thinking, “going good!”. Next thing I see, it’s 236 and going up!. So I corrected w/ a mere 0.5 units of short-acting insulin. At 2:30 I was on my way to going hypo.

In my continuing attempts to figure out what is going on, I think it is either one of three issues:

  1. It’s a hormonal rebound effect (liver is like, “body needs glucose, so I’m sending lots of it out”), which may be due to just recently getting insulin treatment and my body still trying to get used to normal blood sugar levels;
  2. Seconding what Terry4 said, it may be a timing issue - seemed like correct timing for a while, but ultimately food “ran ahead of” insulin, which then ultimately caught up w/ the food (bringing glucose levels back down);
  3. Or it may be just not enough insulin - i.e. insulin seemed to be enough to work for the first 2 or 3 hours after eating, but ultimately wasn’t enough, so after that glucose levels go high. In this scenario however one would expect glucose levels to not ultimately go down enough, which this has happened to me as well.

Anyway, it helps me to know someone else has this issue, b/c I’ve searched so much to try and find what is causing this, so I hope my post is helpful for you as well (at least to know you’re not alone). Also just started reading the book “Think Like a Pancreas” (3rd ed.), and he has mentioned several times the issue of “rebound highs” that can occur after going low (or what your liver may incorrectly think is too low).

I constantly get these when I exercise after a meal when my blood sugar starts to increase. Exercise will cause my curve to come down but shortly after finishing exercise, I will see my sugar slowly creeping back up.