The term ‘blood sugar level’ refers to the amount of glucose circulating in your blood. Though glucose is essential to generate energy, having high concentrations of blood glucose over a long period of time can severely impair your health. Glucose is considered to be the principal source of energy for body cells. Under normal circumstances, one can never get ‘high blood sugar’ due to the constant regulation of sugar levels, which occurs when our body is in homeostasis. This protective mechanism works to maintain a stable internal environment by regulating many variables, such as blood sugar.

Certain conditions and situations can interfere with the regulatory mechanism. That’s when there is a danger of developing high blood sugar, or in technical terms Hyperglycemia. Testing yourself for sugar is easy and can be done at any given moment through a simple fingerstick test. Knowing what a normal range is can be life saving. Ideally, fasting sugar should be less than 100 mg/dl and random sugars less than 140mg/dl. Hyperglycemia is a hallmark sign of diabetes but can be elevated in non-diabetics for several reasons.


Common causes of hyperglycemia

  1. An illness or injury stressing your body – Any condition that stresses your body including acute illnesses like cold and flu can cause sugar levels to skyrocket. As a response, stress hormones like cortisol and catecholamines increase the output of sugars from liver, in turn elevating blood sugar concentration.
  2. Too much eating – Snacking in between main meals can overload your body with sugars, hampering the regulatory mechanism.
  3. Inadequate physical activity – when coupled with overeating this can be hazardous.
  4. Dehydration – When we are dehydrated our blood volume goes down, which increases the ‘relative’ blood sugar level.
  5. Diabetes – Diabetes is the most common cause for ‘persistent’ hyperglycemia as in most other instances the sugar spike is temporary. There are two main variants: Type 1 and Type 2. In Type 1 insulin is not produced at all. All insulin sources must from outside sources such as foods or medicines. Type 2 individuals produce small, however inadequate amounts of insulin. The body has difficulty recognizing it and resists. In both types hyperglycemia is characteristic.

It is vital to know that a single instance of elevated blood sugar cannot establish diabetes. ‘Persistent elevation’ is key. Testing must be repeated at a later date to confirm the presence of diabetes. An isolated event can be due to a number of causes. The most common are mentioned above.

To prevent the dreaded complications of high blood sugar it’s important to know the symptoms that identify an episode. Common symptoms include dry mouth, relentless thirst, blurred vision, exhaustion, frequent urination and repeated infections. The most common symptoms are skin and bladder (cystitis) infections. However due to high sugar content present in bodily fluids, almost ‘any’ infection is possible. If you are experiencing these symptoms contact a diabetic care team. Failure to identify and manage these symptoms can further elevate sugars and lead to DKA (diabetic ketoacidosis or HONK (hyperosmolar nonketotic coma) which can be life-threatening.


Results of persistent blood sugar elevation

  1. Heart disease – This is the most common cause of death in diabetics. Chronic hyperglycemia can increase the LDL (bad) cholesterols creating a risk for coronary disease. Recent studies have found a relation between insulin resistant hyperglycemia and hypertension. When a patient is experiencing both, the risk will be doubled.
  2. 2. Diabetic kidney disease – Excess sugars can damage the capillaries in kidneys that drain waste products, promoting kidney failure over time. The amount of urine expelled from the body gradually decreases and excess fluid accumulation causes the body to swell. The risk is higher if blood pressure and cholesterol levels are high. Without proper glycemic control the kidneys stop working completely and need to be put on dialysis.
  3. 3. Diabetic neuropathy (nerve disease) – Also caused by ‘sugar damaged’ blood vessels. Injury to the tiny vessels that nourish nerves can become neuropathic. The effects depend on the affected nerve and range from numbness and pain in extremities to problems in the heart, bowels, and bladder. Regardless, with meticulous blood glucose control nerve damage progression can be slowed and even prevented altogether.
  4. Diabetic retinopathy (eye disease) – This is caused by progressive damage to the capillaries that supply the retina which results in impaired vision and sometimes blindness. Usually this is managed by regular eye check-ups and glycemic control.
  5. Skin complications – About 1/3 of people suffering from diabetes/hyperglycemia develop skin infections, commonly bacterial and fungal at some point in their life. Bacterial infections include folliculitis (hair follicle infection), styes (infection of the eyelid), boils and abscesses. Common fungal infections include athlete’s foot, ringworm (a ring-shaped itchy patch), and vaginal infections caused by Candida Albicans.
  6. Hyperglycaemia during pregnancy – Pregnancy can be complicated by Type 1, Type 2 and gestational diabetes. High blood sugar prior to 13 weeks of gestation can cause serious birth defects and miscarriages. Blood sugar control must start before attempting to conceive for Type 1 and Type 2 sufferers and must be maintained throughout the pregnancy. Poor blood sugar control in the third trimester can cause macrosomia (high fetal weight). This has potential to complicate labor and delivery and possibly harm both the mother and her baby.

As you can see, the complications are quite notorious, demanding early identification and management. However, with correct behavior modifications and treatments most individuals with high blood sugar can prevent or delay any onset of any complications.




1.williams textbook of endocrinology 10th edition,chapter 31-complications of Diabetes Mellitus p.1802-1882

2.High Blood Glucose: What It Means and How To Treat It

3.Stress Induced Hyperglycaemia

4.Hyperglycemia (High Blood Glucose)

5.Cardiovascular Disease & Diabetes

6.Diabetic Nephropathy – Topic Overview