BG levels when sick

I have only had cold viruses since diagnosis, and they haven’t affected my BG levels. This afternoon I’ve had what I think is just GI distress from another health issue, but also could be a stomach virus. My BG has stayed steady, even with vomiting once, and I’m not on basal insulin so no IOB. I know YDMV, but do BG levels always rise for diabetics with stomach viruses?

1 Like

Always rising would be a godsend. The problem we have when we have stomach bugs is after the initial rise and treatment his bg is hard to keep up, it just wants to go down. We have been fortunate in that we have always been able to keep some gatorade or juice down, but we usually spend much of the illness trying to drive the bg up so we can give extra insulin to deal with the ketones.


Thanks for the reminder to check for ketones…thought of it earlier but had forgotten. I don’t know if it’s just that my pancreas is able to handle this ok or what, but I’ve been pretty flat since lunch (when I started feeling bad). I need to check with my meter to make sure my Libre is accurate…been between 80-100.

1 Like

If you bg is in that range while sick, I would consider it a win. It may not always be this easy. But yeah, checking ketones when sick is a good thing to remember. We usually do it twice a day if he is sick enough to stay home.

1 Like

Yeah, I’m not sure yet if I am sick or not…too many health issues means it’s always very hard to tell until either I’m feeling like I’m at deaths door or someone else in the house gets sick. Just was curious if my steady BG could give me any hints. :stuck_out_tongue_winking_eye:


My experience with stomach issues is that my BG goes low. I haven’t had stomach issues involving vomitting in a long time (since high school days), but I have had an upset stomach lasting hours from other causes (allergic reactions, illness, who knows what). In those instances, I’m always fighting to keep my BG up. Usually when I’m sick my BG goes high, so if I were sick and has a stomach upset, I think it would be a big rollercoaster.

1 Like

For us, it typically goes up for most infections except for when he starts throwing up. In that case, we have had some cases when it went down instead.

The super classic pattern, for us, is to see his insulin needs rise out of the blue—then two days later we find he is coming down with a virus. Then he goes up further. Then its starts going up and down randomly. Then it goes down, way after the symptoms are gone—at which time we have to fight sustained lows (of course, we need to adjust basal down then).

1 Like

I have never once checked ketones, but I see people mentioning it constantly, particularly on the fb pages. At docs appointments I’ve had small amount so of urine ketones and they just say it’s no concern just from eating low carb and working out… am I like the only one not doing it?

Seems like half the country’s on some kind of Atkins/keto diet nowadays, I don’t understand the concern unless blood sugars are wildly out of control

1 Like

For those with a normal diet, ketones are only a problem when high: above 250 or 300 (some even say 350). But when you are high and you have ketones, you can go quickly on the road to DKA.

When we are high with ketones we are ready to take more risks with higher insulin doses.

Personally I’d check for ketones if you’re seriously sick.You can develop dangerous levels of ketones even with fairly normal BGs…we have had it happen twice with Samson. Like people are mentioning, with a stomach bug you can develop high ketones while struggling to keep your BG up. Plus, even though the ketone strips are expensive per strip, if you test like once every three or four months, it’s really not that big of an expense.

1 Like

Whats the point of checking for them? Do they prompt a different course of action? Do you go to the ER if they’re high even if your bg isn’t normal?

well you need more insulin when you have ketones. So even if your’e low, you need more insulin to clear the ketones. So yes, you may need to go to the ER if you have high ketones AND can’t keep your BG up. If your BG is high AND you have ketones, you need to give yourself 10%, 25% or even 50% more insulin than you’d imagine to clear all the ketones, otherwise you could wind up getting sicker.


I don’t test for ketones either @Sam. I did have trace amounts a couple times when I was a child, but it was very obvious that something was wrong because I was vomiting every 30 minutes until the ketones went away.
I have a ketone meter handy, so if I needed to test for them I could. It’s been at least 10 years since I tested though because I haven’t had symptoms like that. I also don’t have a lot of problems with high blood sugars when I’m sick though, so it might be easier for me to stay below 250 than it is for someone who does have trouble with highs while sick.

1 Like

Testing for ketones when you are sick (esp GI bugs) is very different than from when you’re normal. I pretty much never test when not sick, because I almost never have them beyond trace even when my blood sugars are really high (300+), unless I’m losing weight (in which case trace/low are fine). But not checking for them when it turned out I had salmonella is how I ended up in the ER/ICU with bad DKA when I was 18. I had to stay in the hospital for a week, and it took about a month for me to fully recover. (I also ended up with permanent mild artery damage in my wrist due to their doing a blood gas on me when I was super dehydrated.) My blood sugars were high but not super high—in the 200s I think—but I wasn’t eating pretty much anything, so I was taking relatively little insulin to avoid a low, instead of smacking it down hard, which is what I needed to be doing, and either using glucagon or going to the hospital for glucose and insulin IVs if I really couldn’t eat anything for an extended period of time. Don’t make my mistake—check ketones when you’re sick and respond to them aggressively.

(Also worth noting that this is primarily relevant for people with full-blown T1, and probably doesn’t apply as much to folks with early stage or more mild LADA.)


That’s a horrible experience. I’m sorry you went through that cardamom.

Sounds pretty complicated though. If you can’t keep stuff down, then that’s a hard balance to walk. Seems like a really good time to check for ketones. I don’t remember the last time I had a stomach bug- it’s been forever! If I get sick, I always get colds. I probably should have said that in my post.

Good advice to always check for ketones with a bad stomach bug.

1 Like

Thanks! Yeah, it sucked a lot, and I didn’t even get into the full story of all the subsequent problems that happened thanks to my ICU stay—if you can avoid that, do it, because once you are inpatient in a hospital, it’s super easy to get secondary infections etc. Much better to, if necessary, go to the ER much earlier in the whole deal and be able to get an IV for a bit but then go home. On a lighter note though, when all that happened, it was just after my parents had gotten cable tv for the first time ever, so I basically spent that month recovering reveling in that and watching every Law and Order episode filmed to date.

Yeah I think stomach bugs get tricky bc you can end up decreasing TDD a lot because you aren’t eating anything (while your insulin needs may simultaneously be elevated due to being sick), and DKA is caused by lack of adequate insulin, rather than high blood sugars exactly. My blood sugars never seem that reactive to colds (slightly elevated maybe, but nothing severe), so I don’t worry about them too much in regards to DKA either. Stomach viruses like noroviruses are also tricky bc they are one of the few things hand sanitizer does not kill (just good old fashioned hand-washing)… and I know there’s one going around where I am, so be careful out there folks!


Well, I definitely have a stomach virus, but I guess still being in the honeymoon stage of LADA is an advantage here - BG has stayed between 80-100 almost the entire time (no IOB and no food). I did check for ketones when vomiting, but thankfully had none. Started eating again this morning, so Idon’t think there should be any more concern there.

@cardamom, I am sorry for your bad experience! :slightly_frowning_face:

Thanks for all the input. I haven’t had a stomach virus in years, and I was really nervous about being sick with IOB, but managed to not vomit until all my bolus insulin had pretty much worn off.

I did have trace amounts a couple times when I was a child, but it was very obvious that something was wrong because I was vomiting every 30 minutes until the ketones went away.

When you say trace amounts, you mean in urine? Because trace amounts in blood shouldn’t make you sick…

Yes, I don’t think ketone meters were around back then. Maybe they were, but we didn’t know about them.

We used strips that changed color based on the amount of ketones in your urine.

I don’t really understand how people can have ketones and not be sick. Maybe it’s because they’re just ketones in blood vs. urine. Based on my limited experience with just trace amounts of ketones in my urine, ketones are absolutely horrible. I only had trace amounts for 1.5-2 hours on two occasions, and I felt really, really awful both times.

If I’m having problems keeping food down, and my BG is high or rising or my BG is low and won’t rise, and my ketones are high, then yes, I would go to emerg. If all the above but my ketones are low or normal, I might take a “wait and see” approach and stick it out longer at home.

And as @TiaG says, even without being ill, if my BG is high and my ketones are high, I find I need more insulin to bring down the BG than if my BG was high and my ketones were normal.

1 Like