Symptoms of High Blood Sugar: Hyperglycemia

by humagaia

Symptoms of high blood sugar (hyperglycemia) correspond with many of the symptoms of diabetes, unsurprisingly as a diabetes diagnosis relies on testing for high blood glucose.

The symptoms of high blood sugar (hyperglycemia) are often overlooked and mistaken for symptoms of other diseases and conditions.
This makes it very difficult for an individual to determine that their blood glucose is not being used up efficiently.
Rather than rely on recognising the symptoms, it is much better to test blood sugar levels, on a regular basis, with blood testing monitors, to see if levels have raised beyond the normal range.
This can be undertaken cheaply and easily at home, for all the family.

High Blood Sugar : Hyperglycemia

At what point does our blood sugar level become high?

The first thing to note is that US and UK measurement units for blood sugar are different. The US measurement is in mg/dl (milligrams/decilitre) and the UK measurement is in mmol/l (millimols/litre). Confusing I know, but all we need to be aware of is that a normal range for blood sugar is between 72 mg/dl and 144 mg/dl (US), or 4 mmol/l to 8 mmol/l (UK). From now on I will dispense with the mg/dl and mmol/l bit and concentrate on the numbers.

Please note: the numbers above detail the range that is normal.

This means that, at different times of the day, and different times within the cycle of eating, our blood sugar levels, if measured, should be found to be within these ranges.

When we eat, and for about 2 hours after we eat, our blood sugar level will be in the upper part of that range.

When food has been digested, or when we undertake vigorous exercise, the measurement will fall to the lower end of the range.

Having a meal
Having a meal

If we average out the measurements over a day, then our blood sugar average measurement should be about 90 (US) or 5 (UK) - this is a very rough estimate, as normal blood sugar levels are different, within the range, for different individuals.

Outside of the range, over 8 (UK) or 144 (US) for high blood sugar (hyperglycemia), is considered to be a symptom of diabetes. That is, if the condition of being outside the range is regular or consistent. There are times when singular fluctuations can occur, especially after a heavy meal.

As far as hyperglycemia is concerned, a level consistently above 7 (UK) or 126 (US) is deemed to be high, and an indicator that diabetes is present. The best way to determine whether your body is hyperglycemic is to test your blood with a blood sugar monitor.

Blood Sugar Monitors

The best way to test for high blood sugar or low blood sugar levels

Hyperglycemia Wiki

Hyperglycemia or Hyperglycæmia, or high blood sugar, is a condition in which an excessive amount of glucose circulates in the blood plasma. This is generally a glucose level higher than Reference ranges for blood tests or 11.1 |mmol/l] ...

Symptoms of Diabetes

Diabetes 1, Diabetes 2 & Diabetes Incipidus.

Now that we know what constitutes hyperglycemia, the next question is 'What are the symptoms of high blood sugar (hyperglycemia)?'. But before we go into that, we must be aware that high blood sugar levels are in themselves a symptom of diabetes, of which there are several forms.

Unfortunately, this is where things get a little confusing. Almost all symptoms of high blood sugar are also symptoms of other conditions. We could have a symptom which could indicate hyperglycemia, but it could equally indicate the onset of a cold, or kidney disease, or a urinary infection, or.......the list goes on. 

Cure diabetes
Cure diabetes

Sorry to introduce another complication, but it is important to understand that symptoms are one thing, causes are another.

The symptoms of Diabetes Mellitus (Diabetes 1 & 2) and Diabetes Insipidus correspond. Signs of diabetes are the same for different diabetes types but diabetes 1, diabetes 2 and Insipidus have different causes. Discreet diabetes signs for these three diseases can be difficult to spot and have many similarities. 

So, what are symptoms of diabetes?

Diabetes 2 symptoms are the most difficult to spot. An undiagnosed diabetic often has no diabetic signs. There is no set of symptoms that is generic. Diabetic symptoms may be very mild. Type 2 diabetes goes unnoticed because the symptoms could be associated merely with getting older. Older people are more susceptible to diabetes, so this is a hindrance to diabetic diagnosis. One has a gradual raising of blood glucose levels, over time. Diabetes 2 is an insidious disease that creeps up on you and says 'boo' when you least expect it.

Diabetes 1 onset is rapid. Like being hit by a car whilst on a pedestrian crossing.

It is sudden and devastating.

Diabetes 1 Mellitus happens to younger people that would not assume diabetic symptoms to be a function of age.

For gestational diabetes, onset is a function of the condition. There is an obvious cause and it will be diagnosed in the general course of events. Testing of your blood when you are pregnant is a consequence that you cannot avoid.

But one factor present with all types of diabetes is high blood sugar (or glucose).

Type 1 diabetic
Type 1 diabetic

Symptoms of High Blood Sugar


There are two types of symptoms, for all types of Diabetes.

Unfortunately not all symptoms will be present for any particular sufferer, and in many cases there will be no symptoms at all.

The two type are:

  1. Functional

  2. Physical

Here I will concentrate on those symptoms of diabetes that are also the symptoms for hyperglycemia.

Diabetes supplies
Diabetes supplies

Functional Symptoms of High Blood Sugar

Functional symptoms are the symptoms that are manifest in the daily functions that your body undertakes:

  • Bowel movements:
  1. You may see an increase in the number of times you need to pee (urinate [polyuria]), and the amount you pee at each session. It may be subtle changes to begin with, that you could put down to age - hence the possibility that this symptom is ignored. 
    As diabetes progresses, and remains untreated, the quantity and frequency increase. 

Bowel movements
Bowel movements

It's the body mechanism that flushes out the excessive glucose in the blood. 
Increased peeing is not confined to daytime - it follows that an increase in blood-glucose due to diabetes does not go away in the night, let alone overnight. 
In extreme cases where no treatment has been started, the quantity of pee produced is huge. In my case, in the latter stages, just before I went into a coma, I was peeing around 1/2 pint every 30-40 minutes, throughout the day and night.

2. You may find that you suffer more from constipation. Again, because this is a function of getting old, and can occur for many reasons other than Diabetes, it is invariably not taken as a sign that high blood sugar is present.

3. The silly thing is that you may alternatively suffer from bouts of diarrhoea, which seems incongruous with the symptom of constipation. It is the extremes of bowel movement that are the symptom.

  • Thirst (polydipsia) - you may notice that you feel thirsty more often, and that your thirst is not quenched easily. Where the disease has progressed to the stage where high blood glucose levels are having a devastating effect on your body, it is not surprising that thirst is a symptom. Half a pint every 30 to 40 minutes does not sound a lot in itself, but when you add it up that's 36 to 48 pints a day. This must be replenished somehow.

Need to Replenish Fluids

  • Hunger (polyphagia) - if you find you are getting the 'munchies' more often, then this could be a sign that your blood-glucose levels are increasing. 

    This is a 'self-fulfilling' prophecy of doom. 

    Body weight is thought to be a contributing factor in contracting diabetes, but it may also be a consequence of diabetes. 
    The more you eat, the more likely it is that you will be diagnosed with diabetes. 
    The greater your blood-glucose level, the more likely you are to have hunger pangs, and subsequently to eat more. 

Symptom of Hunger


Physical Bodily Manifestations of High Blood Sugar

Physical manifestations are the physical signs, on or about your body, that are a little more prevalent than normal, when high blood-glucose levels are sustained:

Tiredness and Fatigue
  • Tiredness and Fatigue - you feel as though all the energy has been drained out of you, and it leaves you with the 'I can't be bothered to do anything' feeling.

    A sort of malaise washes over the body, and can have a serious effect on motivation, and coping with life. 

  • Blurred Vision - again, this is a symptom that is often put down to getting older, and is ignored. 
    In this case it is due to alterations in the shape of the lens of the eye, caused by dryness (osmotic effect) - the blood-glucose 'soaks up the fluid'.

  • Dry skin - who doesn't have dry skin? High glucose levels in the blood draw moisture from anywhere it can get its hands on. 
    Women pay a fortune to cosmetic companies to get rid of dry skin. However, it is more the production of more dry skin than normal, that is the symptom.  It is where you notice a marked increase. 
    Dryness, peeling and itchiness of the skin on the feet is the main sign that something is amiss. 
    I have not seen this one mentioned elsewhere, but I get dry skin in my ears, and it can be particularly irritating and annoying.

Products to alleviate dry skin
  • Slow-Healing Sores - especially on the feet, but also on the legs and elsewhere, can be suppurating in the worst cases.

  • Blood Infections - I have not seen it mentioned anywhere else, but I suffered with, over a long period of time, abscesses which required surgery, and frequent eye infections. I am speculating that these could have been warning signs that not all was well with my blood.

  • Skin Infections - I have not seen details of what type of skin infections may be a symptom of high blood sugar, but I presume it is ulcers and the like, that would point in the direction of a blood-glucose problem.

  • Nerve Effects - again, often, these can be put down to age and the deterioration of our body with age. Here I am specifically talking about tingling and numbness in the hands and / or feet. 
    With the hands, this is a function of 'carpel-tunnel syndrome' which is in turn one effect of rheumatism. So it is difficult to differentiate whether it is that or diabetic sugar levels, that is the cause. 
    In addition, especially with Type 1 Diabetes, cramping of the muscles can be an issue. This can be due to the levels of potassium in the blood, affected by the ratio of sugars to liquid in the blood. It is very important to take any nerve issues seriously, as this could indicate that diabetes is well-advanced. Nerve damage is a long-term effect of high glucose levels in the blood, and is very serious. It's end-stage is neuropathic damage which can lead to amputations.



The symptoms of high blood sugar (hyperglycemia) are the same symptoms as for diabetes, but they are also the symptoms of many other diseases and conditions, not least of which is that of ageing. As we grow older, insulin function diminishes, especially if your family is prone, through genetics, to diabetes.

Do not assume that any one symptom means that hyperglycemia is present. 

Equally, do check your blood glucose level if any of the above symptoms are manifest.

The symptoms of high blood sugar should never be put down to just getting older. Get a check-up with your medical practitioner should any symptom of high blood sugar affect you.

Previous Diabetes Article

What is diabetic coma? It occurs when our blood sugar range rises too high (hyperglycemic coma), or when our blood sugar range falls too low (hypoglycemic coma).

Next Diabetes Article

Diabetic coma through high blood sugar (hyperglycemia) is completely preventable. That is if you know the symptoms that warn that diabetic coma is imminent. I did not take notice..
Updated: 09/20/2012, humagaia
Thank you! Would you like to post a comment now?


humagaia on 08/24/2012

@2 I did not get a burning feeling and I have not seen that mentioned elsewhere. My manifestation was the need to drink the equivalent of several glasses of liquid, then within half an hour, to do the same again. I think diabetes has an effect on the hyperthalamus in the brain, which controls hunger and thirst.

humagaia on 08/24/2012

@K - you never know when it is going to hit, so everyone should be made aware of the signs they should look out for.

2uesday on 08/23/2012

The two people I know who have been diagnosed with this both had the unquenchable thirst symptom. One described it as a burning feeling in their throat that made them want to drink ice cold water.

katiem2 on 08/23/2012

Good to know, I have a brother with Diabetes. It hit him suddenly in his forties. Hmmm I like your how to avoid diabetes article, will review that now. Thanks :)K

humagaia on 03/26/2012

Numbing of the toes is a symptom and a complication of diabetes. I am in the process of writing an article on the complications of diabetes.
Although numbness can be a symptom of diabetes, like most symptoms, it can be something else causing it.
You should consult your medical team to determine the cause.

FinancialTips4U on 03/26/2012

Thank you for this extremely informative page humagaia. Is numbing of the toes a symptom of Diabetes or is it usually the whole foot?

humagaia on 03/05/2012

Brenda, but before reading it, you weren't sure?

BrendaReeves on 03/05/2012

Well, after reading this article, I'm happy to say I'm healthy.

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