Hyperglycemia vs Hypoglycemia: Difference, Symptoms, and Treatments
Written By Kobi Nathan, Pharm.D., M.Ed., CDP, BCGP, AGSF
Sleep Disorders
September 11, 2022

It is normal for our blood sugar (glucose) levels to rise and fall throughout the day and night.

Our sugar levels fluctuate based on the level of physical activity, meal consumption, sleep, or diurnal activity.

Normal blood glucose levels in people without diabetes range between 60 and 140 mg per deciliter (mg/dL). For those who use SI units, this translates to a range between 3.3 and 7.8 millimoles per liter (mmol/L).

Levels that fall outside the normal range are quickly corrected by the body primarily through two main hormones: Insulin and Glucagon.

Specifically, suppose sugar levels rise too high. In that case, the beta cells in the pancreas secrete insulin to shuttle the excess sugar into your muscle, fat, and liver cells, thereby lowering the sugar circulating in the blood.

Conversely, if glucose levels fall too low (hypoglycemia), your pancreas releases glucagon.

This hormone then triggers your body to release stored glucose in your skeletal muscles and liver (and small amounts in your brain), called glycogen, and converts it back into glucose, which is released into the bloodstream. This process is called glycogenolysis.

Infrequent episodes of high blood glucose do not result in severe danger to life. However, this is not the case for hypoglycemia. As I will explain below, even one instance of hypoglycemia can result in death!

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performance lab

Acceptable glucose level ranges for older adults with diabetes

The blood sugar targets for older adults with Type 2 diabetes are slightly different. The table below provides an overview of blood sugar targets based on an older adult’s health condition and the reasoning as to why.


Blood Sugar Goals for Older Adults with Diabetes

Patient characteristics/
health status
A1C goal
Fasting or
Bedtime glucose
Healthy (few
coexisting chronic
illnesses, intact
cognitive and
functional status)
Longer remaining
life expectancy
Less than 7.0 to 7.5%
(53–58 mmol/mol)
80–130 mg/dL
80–180 mg/dL
(multiple coexisting
chronic illnesses or
2+IADL* impairments or
remaining life
high treatment
fall risk
Less than 8.0% (64
90–150 mg/dL
100–180 mg/dL
Very complex/poor
health (Long term care or endstage chronic
illnesses, or
impairment or 2+
ADL** impairments)
Limited remaining
life expectancy
makes benefit
Avoid reliance on A1C;
glucose control
decisions should be
based on avoiding
hypoglycemia and
100–180 mg/dL
110-200 mg/dL (6.1-11.1 mmol/L)
Adapted from American Diabetes Standards of Care, 2022; https://diabetesjournals.org/care/issue/45/Supplement_1
*IADL = Instrumental Activities of Daily Living
**ADL = Activities of Daily Living


Please read my article here for a detailed explanation of ADLs and IADLs.

The table shows that glucose targets are much more liberal in older adults than younger people. The rationale provided in the table provides a peek into why this is so.

When we are younger, our healthcare providers stress the importance of strict control of diabetes through lifestyle, and diet changes, including appropriate medication therapy.

As mentioned above, doctors do this because they want their patients to avoid the long-term damage that inevitably occurs from uncontrolled diabetes/sustained hyperglycemia.

I see this daily in my clinical practice – people in their 30s and 40s suffering from diabetic neuropathy (nerve pain) in their feet and legs, their kidneys damaged so severely that they have no choice but to go on dialysis, suffering from diabetic blindness, life-altering strokes, heart disease, cerebral small vessel disease (CSVD), and other health problems.

So, yes…we want to be aggressive with the management of diabetes in younger people. However, things change as people get older. In actuality, we want to ease up on the aggressive management of the disease in the elderly.

I know – it sounds counterintuitive, doesn’t it? Wouldn’t we want to be strict with our older loved ones’ glucose control? Let me explain why…

Older adults in their 60s, 70s, 80s, and beyond typically have other chronic medical problems, such as heart failure, high blood pressure, dementia, functional decline due to normal aging, and frailty. Polypharmacy or overmedication are additional risk factors and add significantly to this health burden.

Because of all these issues, the elderly are at much higher risk for hospitalization and premature death. One of the biggest culprits is the overtreatment or aggressive management of diabetes, usually through inappropriate prescribing by medical providers or medication overdosing due to confusion, cognitive, and functional decline in the older adult, resulting in episodes of hypoglycemia.

Older adults with diabetes have a higher risk for recurrent hypoglycemia than younger adults.

The following scenarios are all too common with older adults:

  • The 78-year-old widow who was prescribed 5 mg of glyburide (a diabetes medication that should NEVER be prescribed to an older adult) to be taken twice daily, resulting in a hypoglycemic event
  • The 87-year-old who was still on a meal-time and night-time (basal-bolus) insulin regimen, experiencing multiple hypoglycemic episodes, was found on the floor of his apartment, on the brink of death, by a Meals-on-Wheels staff member
  • The 73-year-old with undiagnosed dementia who is still taking meal-time insulin, forgets that she just injected her insulin, takes another insulin dose, and then forgets to eat her meal
  • And so on…

My warning to all my elderly patients and their caregivers is this: It takes only ONE hypoglycemic event to kill!

What complicates this whole issue even more, is that older adults do not present with the usual symptoms of low blood sugar. Again, let me explain…

In a younger person, the signs and symptoms of hypoglycemia (any level below 70 mg/dL) are very evident. The bulleted description and image below describe these:

Signs and Symptoms of Hypoglycemia

  • Pounding heartbeat (palpitations)
  • Feeling very hungry
  • Feeling shaky or trembling
  • Extreme sweating
  • Tiredness
  • Dizziness
  • Blurred vision
  • Easily irritable, anxious, moody, or tearful
  • Coma, death (in severe hypoglycemia)


signs of hypoglycemia

Image credit: https://www.mpqhf.org/


Conversely, the situation can be very different with an older adult. The symptoms you see above may not necessarily show in your older loved one.

In fact, symptoms can be very non-specific. Sweating, fast heartbeat, anxiety, hunger, irritability, and all the other symptoms that we see in a younger adult may be absent in the elderly person (hypoglycemia unawareness).

Your loved one could be sitting comfortably in her chair or bed, exhibiting none of the signs and symptoms typically seen, and her blood glucose level could be 25 mg/dL! (remember – a hypoglycemic reading is anything below 70 mg/dL or 3.9 ). This situation is entirely possible – I have seen it many times in my clinical practice.

Hence, your loved one may be on the brink of death, and you may have no idea how dire their situation is. Extra care must be taken to ensure that your older loved one’s blood sugar levels are constantly checked.

Other challenges in recognizing hypoglycemia in the elderly:

  • Any observed symptoms could be misdiagnosed or overlooked
  • Any behavior change or agitation could be misinterpreted as dementia-related symptoms
  • Hypoglycemia could manifest as confusion or hypoactive delirium
  • Inability of older adults with dementia to communicate their symptoms or feelings to loved ones (

Consequences of hypoglycemia in older adults

  • General physical function decline
  • Reduced ability in performing activities of daily living
  • Complete dependence
  • Frequent falls
  •  Increased risk of fractures including hip fracture
  • Frequent hospitalizations
  • Increased risk of vascular disease
  • Impaired cognitive function
  • Increased risk of dementia
  • Increased fear and anxiety
  • Increased social isolation
  • Behavioral changes
  • Increased panic attacks
  • Increased risk of frailty
  • Increased risk of disability
  • Increased risk of death

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4365959/#!po=11.9048

Managing hypoglycemia in older adults

The American Diabetes Association (ADA) recommends managing hypoglycemia symptoms with the “15-15 rule.” If your blood sugar level dips below 70 mg/dL (3.9 mmol/L), do the following:

  1. Consume 15 grams of fast-acting carbohydrates to increase your blood sugar quickly
  2. Re-check your level 15 minutes later
  3. If your blood sugar is still below 70 mg/dL, consume another 15 grams of carbs
  4. Repeat until your glucose level is at least 70 mg/dL
  5. If your symptoms don’t get better, or your glucose does not increase to 70 mg/dL, call 911 or your doctor immediately)

If you don’t have access to a blood glucose meter, do the above procedure until you start to feel better.

**Note: if your loved one is unconscious, DO NOT do put anything in their mouth! You could cause them to choke on the food item or drink. This is a MEDICAL EMERGENCY and you need to call 911 immediately!

What are some examples of 15 grams of a quick acting carbohydrate?

  • 1/2 banana
  • 1 small fruit (apple, orange, etc)
  • 2 tablespoons of raisins
  • 1 tablespoon of honey, corn syrup, or sugar
  • 1 tube instant glucose gel (available at any pharmacy)
  • 3 peppermint candies (not sugar-free)
  • 3-4 glucose tablets (available at any pharmacy)
  • 4 ounces (half-cup of fruit juice or soda (NOT diet or sugar-free!)
  • 5 Live Savers candies (not sugar-free)
  • 15 grapes
  • 1/2 cup applesauce

What is Hyperglycemia?

Hyperglycemia or high blood sugar levels (any level over 180 – 200 mg/dL) can happen to anyone. You don’t have to have diabetes to have it.

Causes of hyperglycemia in people without diabetes

If you don’t have diabetes, hyperglycemia can occur due to any of the following reasons:

  • Polycystic ovary syndrome (PCOS)
  • Cushing’s Syndrome (when your body produces too much of the stress hormone, cortisol)
  • Active infection (body releases high levels of stress hormones such as cortisol and adrenaline)
  • Obesity
  • Lack of exercise/physical activity
  • Family history of diabetes

Causes of hyperglycemia in people with diabetes

If you have diabetes, hyperglycemia is the main problem that you will be fighting daily. If you have type I diabetes, your pancreas is unable to produce insulin to force excess glucose out of the blood and into your cells.

If you have type 2 diabetes, your pancreas is not producing enough insulin. Additionally, there is insulin resistance in your cells, preventing glucose from being shuttled inside them.

If you have uncontrolled diabetes, the consequence is slow and chronic damage to the blood vessels, nerves, and organs in your body.

Health consequences of hyperglycemia

If left untreated, hyperglycemia can lead to many health problems such as:

  • Cardiovascular/cerebrovascular disease (heart attacks/strokes)
  • Kidney disease (end-stage renal disease requiring dialysis in the worst cases)
  • Nerve damage [numbness, tingling, shooting pain, down the extremities, diabetic retinopathy (vision loss), diabetic gastroparesis (trouble digesting and moving food along)]
  • Decrease in bone quality, leading to osteoporosis/fractures
  • Infection and slow healing, leading to gangrene and amputation
  • Premature death


Signs and Symptoms of Hyperglycemia

The bulleted description and image below describe the signs and symptoms of hyperglycemia:

  • Extreme thirst, drinking a lot, and subsequent frequent urination
  • Hunger
  • Blurry vision
  • Frequent infections (thrush, urinary tract infections)
  • Trouble concentrating
  • Rapid and unintentional weight loss within a few weeks
  • Sores that are not healing
  • Dry skin
  • Dry mouth
  • Nausea/stomach pain
  • Muscle weakness, noticeable loss of energy
  • Fatigue
  • Generally feeling unwell
  • Confusion, drowsiness, and coma
  • Fruity breath (one of the warning signs of diabetic ketoacidosis, a life-threatening condition)




symptoms of hyperglycemia

Image credit: https://www.mpqhf.org/


You should seek immediate medical help or call 911 if you have ongoing vomiting and diarrhea and are unable to keep any food or fluids down, or your blood glucose levels stay elevated above 240 mg/dL (13.3 mmol/L).

Preventing hyperglycemia if you are diabetic

If you are diabetic, you must take your diabetes medication exactly as prescribed by your medical professional, to keep your blood sugar within a safe range (see the table above for acceptable ranges if you are an older adult).

Additionally, it is very important that you monitor your blood sugar regularly. If you have not already done so, ask your doctor about scheduling an appointment with a diabetes educator to help you plan out your medications, diet, exercise, and lifestyle. Inform your health care provider about the exercise regimen you are about to start, as he or she may need to adjust your medication dosing.

Preventing hyperglycemia if you are not diabetic

If you are not diabetic, you can control your blood sugar by engaging in regular physical activity (around 30 minutes of moderate activity daily for at least 5 days weekly).

Avoiding unhealthy weight gain through an improper diet is also important. Avoid refined sugars and carbohydrates, and aim to consume more vegetables and moderate amounts of fresh fruits.

Finally, here are some things you can do to keep glucose levels steady:

  • Eat well-balanced meals with adequate protein intake
  • Regular exercise including resistance and aerobic training as tolerated
  • Aim for modest weight loss (5-7%) in obese older adults, maintain a healthy weight
  • Avoid simple carbohydrates and sugars
  • Dilute juices with water, even if they are freshly squeezed
  • Get enough sleep



  1. https://diabetes.org/healthy-living/medication-treatments/blood-glucose-testing-and-control/hypoglycemia
  2. https://www.healthline.com/health/diabetes/hyperglycemia-vs-hypoglycemia
  3. https://diatribe.org/detecting-signs-hyperglycemia-vs-hypoglycemia
  4. https://www.mpqhf.org/QIO/wp-content/uploads/2019/02/1.22.19_V1_NH-Readmit-DM-Webinar-00_508.pdf
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4365959/#!po=11.9048
  6. https://www.nhs.uk/conditions/low-blood-sugar-hypoglycaemia/
  7. https://www.ncbi.nlm.nih.gov/books/NBK554417/
  8. https://my.clevelandclinic.org/health/articles/23509-glycogen
  9. https://diabetes.org/healthy-living/medication-treatments/blood-glucose-testing-and-control/hypoglycemia#:~:text=The%2015%2D15%20rule%E2%80%94have,at%20least%2070%20mg%2FdL.

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