Endocrinology and Diabetes
Blood Sugar Levels Normal and elevated blood sugar levels before (preprandia) and after (postprandial) a meal
Blood Sugar Levels
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- Let's go little bit into how we can tell whether our body is processing glucose properly
- And whether or maybe we have diabetes
- And I want you all to take all of this with a huge grain of salt
- because I am not a doctor, this is not medical advice
- My goal here is to kind of just explore this subject with you
- and try for all of us to get a better understanding of things
- So let's think about what might happen after we have a meal
- So we draw a little chart over here
- So let's call this "hours"
- And then on the vertical axis, I'm going to talk about our concentration of sugar in the blood
- --so "blood sugar concentration"
- sugar--actually you can call it "glucose concentration"
- "blood sugar", we are talking about glucose
- So let me draw a couple of points on this chart
- So maybe this is 50, and our unit is going to be milligrams per decilitre (mg/dL)
- Actually let me just do it this way, let me just say that everything is in milligram per decilitre
- and we will talk in future videos about how we can relate this unit to everyday terms
- But let's say that this right here is 50, this right here is 100
- this right here is 150, and let's mark it right here at 200
- So let's think about what will happen for a normal person
- Let me mark some hours over here
- so hour 1, 2, 3, 4, 5, 6, 7, 8; that's probably good enough
- So the normal person, when they haven't eaten anything for a long time, let's say greater than 8 hours
- So their fasting blood sugar, will be right around 80 mg/dL, give or take a little bit
- There's a range around that, but I just want to show you what would happen to a normal person
- So 80 mg/dL, their blood sugar should hopefully be right around there
- And sometimes this fasting blood sugar, maybe we are assuming this is in the morning
- maybe this hour 1 is 7am, so they haven't eaten for a while
- that's fasting blood sugar
- This is also, you'll hear in, sometimes your doctor
- I heard my wife say this word without knowing what it meant
- they sometimes say "preprandial"
- Which is a very fancy word, which just means "before a meal"
- "preprandial" is literally "before eating"
- After the meal, you'll talking "postprandial"
- A very fancy word, for a very simple idea, eating
- So let's say at hour 2, this individual eats breakfast
- So this is when the individual is going to eat breakfast
- Now a normal person, when the person eats breakfast there'll be some carbohydrates in that breakfast
- And it will be broken down into glucose, and glucose will enter the blood stream
- And so their blood glucose will go up
- it will slowly go up
- And I was reading some studies, they say it kind of spikes 45 minutes into a meal
- So let's see, 45 min is over there
- so maybe it will go up to about there
- And in a normal individual, the blood glucose level really shouldn't go above 120 mg/dL
- And you know, there's obviously exceptions to all of these
- we're just kind of saying that the normal breakfast, the normal person
- not, you know, they're not eating a pint of honey, doing something crazy
- Let's say 120 would be right around there
- A normal person, you wouldn't, someone who does not have diabetes
- it'll be unlikely that it'll go above that
- And actually about after 2 hours, they're getting pretty close to normal
- they're getting back under 100 mg/dL
- And then you go beyond 2 hours, they just kind of get close back to their baseline
- to the 80 mg/dL
- So once again, this is normal
- and of course, don't freak out if you were to take a blood test one morning and you're like 85 mg/dL
- you're still not far off from normal, so obviously there's some variation from person to person
- Now, if someone has diabetes, if either they have Type I, they don't have enough insulin
- to actually process the glucose
- or, if they have enough insulin, but their body is desensitised
- the insulin is not being processed, so they can't process the glucose
- We'll see that the glucose concentration will go up
- And so in general, if you were to wake up one morning after not having eaten for more than 8 hours
- and you were to prick your finger with little glucose monitors you can get at the drug store
- And in your finger, the blood sugar levels, if you're to find them to be
- let's say you're to find them to be at 140 mg/dL
- it's a good indication, you shouldn't freak out, you should do multiple tests
- and make sure that it wasn't a false reading or any of that
- And you should definitely see a doctor
- Once again, don't take this as any type of medical advice
- that is not the purpose of this. The purpose of this is to understand a little bit of what's going on
- Don't change your lifestyle based on any thing I tell you
- Alright, but if you do experience that, it looks like, at least just from that one data point
- that your body is not processing sugar properly
- because you had over 8 hours to process the sugar
- for insulin to go into your blood steam, and allow glucose to be taken up
- and get back down to normal level
- but it still hasn't gone there
- So if you were to test a value like that, you should be concerned.
- In general, the threshold--I've seen multiple thresholds here--
- are between--I've seen high, and kind of middle one--120-130 mg/dL
- So you're fasting, blood sugar is around this line right here
- remember, the fasting blood sugar, not after you've eaten
- Preprendial, before meal
- if it is above that threshold right over there, then you should definitely at least see a doctor
- and make sure they can see if you have diabetes
- but this will be cause for concern
- Another thing is that after a meal it spikes well beyond that
- if we're talking it gets above 180
- you know, once again, these are just thresholds that, you know, doctors have come up with
- and researchers have come up with
- and say, "hey this is a good indication that somehow you're not processing glucose properly"
- so 180, 180 is up here, I'm drawing this is a squiggly line 'cause it's kind of a range
- you know, it's not like if your blood glucose is 124 you're safe
- and all of a sudden 125 you have diabetes
- you know they're not that different from each other, but they have to set up some thesholds
- so that, just to kind of have a threshold I guess
- so if your blood sugar, after eating a meal, were to spike up to 200
- once again, that would be cause for concern
- In general, if someone has diabetes because they're not processing the glucose properly
- their blood glucose might look something like this
- So maybe their fasting glucose is right around 125-130, they can move around
- then they have a meal, that it might spike up
- obviously they can process some of the glucose, otherwise they would die
- but it's not being processed properly
- so the glucose levels don't go down to where they should
- And maybe some glucose gets taken up from the blood
- obviously they're living, so the cells are metabolising something
- but it never gets to the normal 80 mg/dL
- it might settle down back to something in the 120 range, to something like that
- which would be cause for concern
- And in general if you're some place, I've seen the threshold if you're above 100 on a fasting basis
- that's cause for concern, you should maybe adjust your lifestyle
- And if you're above 120-130 after a meal, once again, you should also be slightly worried
- that you might be prediabetic, or you might have some risk of developing diabetes
- So if someone has blood sugar like this, they're probably diabetic
- and if someone has blood sugar like this, they should be worried
- Once again, I'm not a doctor, don't take any of this as an advice
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