How Does Your Body Tell You That Your Blood Sugar Is Too High?

  • 1st Revision: Tamsin Rose
  • 2nd Revision:Tamsin Rose
  • 3rd Revision: Olivia Sowerby

Exhaustion, frequent urination, dry mouth, shortness of breath, blurred vision, fruity breath smell, constant thirst, and weight loss are all indicators that the blood sugar is high.


Do you always feel exhausted?

Are you frequently visiting the restroom to empty your bladder?

This article will look at the various signs and symptoms that are associated with high blood sugar.

Three important points:

  • Diabetes is characterised by hyperglycaemia, in other words, high blood glucose levels in the body.
  • The most common symptoms of hyperglycaemia are frequent urination, fruity breath smell, increased thirst, fatigue, weight loss, and blurred vision.¹
  • Elevated blood sugar spikes for long periods which, if not properly managed, can lead to life-threatening conditions such as diabetic ketoacidosis and hyperosmolar hyperglycaemic nonketotic syndrome.¹

How is blood sugar regulated?

The pancreas is an organ located in the abdomen; it plays a role in both the digestive and endocrine system (hormone system).⁸

The pancreas has islets cells that produce insulin from the beta cells and glucagon from its alpha cells.

These two substances help balance blood glucose levels in the body, through a negative feedback mechanism, which is called homeostasis.

When the blood glucose level is high, the pancreas produces insulin to regulate the sugar level.

And when the blood glucose level is low, the pancreas produces glucagon to regulate the blood sugar back to normal.


Diabetes mellitus is a health condition characterised by hyperglycaemia i.e high blood sugar levels in the body and imbalance in the breakdown of carbohydrates, fats, and protein.¹

There are two major types of diabetes mellitus:

  1. Type 1 diabetes or insulin-dependent diabetes mellitus.
  2. Type 2 diabetes or insulin non-dependent diabetes mellitus.
  • Type 1 diabetes: is caused when there's autoimmune destruction of the pancreatic beta cells that produce insulin. Patients in this category are placed on insulin for life.
  • Type 2 diabetes: is caused by reduced secretion of insulin from the beta cells or insulin resistance. And patients in this category are given oral antidiabetic medications.
  • Gestational diabetes: is seen in pregnant people assigned female at birth (AFAB). According to Web MD, 10% of people AFAB are affected yearly by gestational diabetes. And people AFAB with this condition may come up with type 2 diabetes in later years.⁷

Hyperglycaemia or High Blood Pressure

Is there a link between high blood sugar and high blood pressure?

Research has shown that most patients with high blood pressure, if not properly managed end up having type 2 diabetes as well and vice versa.

The two conditions share risk factors and underlying conditions.

And they may worsen the symptoms of each other.

High blood pressure and high blood sugar share the following in common: Obesity, Inflammation, Oxidative stress, and Insulin Resistance.

There are three ways in which high blood sugar levels can increase hypertension or high blood pressure:

  • The blood vessels lose their elasticity to stretch causing increased peripheral resistance, which increases blood pressure.
  • The amount of fluids increases in the body, especially in a case whereby the two kidneys are affected, which leads to increased blood volume eventually leading to increased blood pressure.
  • Insulin resistance involves processes that increase the risk of high blood pressure.


Hyperglycaemia is a medical condition that affects diabetes patients (whether type 1, type 2, or gestational diabetes).

It is the medical terminology for an elevated blood sugar level.

It should not be confused with hypoglycaemia, which is the term used to define a state of low blood sugar.

Hyperglycaemia also affects patients who are severely ill i.e having a severe infection, shock, or having a heart attack.

Is it Dangerous?

It depends on the duration i.e for long or short periods.

If it is infrequent and for short intervals, it can be quickly managed and it is not best to let it linger for long periods.

However, in situations where hyperglycaemia happens for a long period, it is dangerous and a very serious situation and it should be properly managed.

Part of the dangers of hyperglycaemia for an extended period is damage to the nerves of the eyes, kidneys, brain, and blood vessels.

The treatment goal in diabetes is to keep the blood sugar level as close to normal as possible.

If hyperglycaemia is not treated, it leads to severe health complications such as diabetic ketoacidosis and hyperosmolar hyperglycaemic nonketotic syndrome.

  • Diabetic ketoacidosis (DKA):Insulin is responsible for taking glucose into the body's cells; DKA occurs when the body is deficient in insulin. Without insulin, cells lack energy. The liver breaks down fat for energy, thus producing ketones in the body; an accumulation of ketones leads to acidic blood. 

    Patients with DKA experience polydipsia (eating a lot), polyuria (passing out urine a lot, weight loss, impaired consciousness, decreased sweating, etc. DKA is more common in type 1 diabetes yet it may occur in type 2 patients. It is usually acute and life-threatening.

Signs you are hyperglycaemic

The following are the signs and symptoms that may ensue when you are hyperglycaemic and you may not notice it early because they tend to develop slowly and may not show you signs at all till the blood sugar is high:

  • Frequent urination:  In a hyperglycaemic state, the kidney works so hard to keep up with the excess glucose in the body; when it cannot keep filtering and absorbing glucose, it excretes water, thereby causing you to urinate frequently.
  • Increased thirst: When the kidney can no longer filter the excess glucose, water is dragged along with the glucose, making you dehydrated and thirsty.
  • Blurred vision: Hyperglycaemic symptoms affect the nerves of the eye, by pulling fluids from the eyes tissues and this affects the ability of the eyes to focus. If left untreated for a long period, new vessels are formed, while damaging the original vessels, which may sometimes lead to vision loss.
  • Headache: Fluctuations in the blood sugar level from low to high, cause you to feel headaches during hyperglycaemia.
  • Fatigue: Increased urination may lead to loss of glucose along with water. In a hyperglycaemic state, the insulin cannot take the glucose needed by the cells, leading to the loss of energy in the cell.
  • Dry mouth: According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), dry mouth or xerostomia is a symptom of hyperglycaemia, which is due to dehydration from frequent urination.⁶
  • Nausea: As the blood glucose level goes low and high, it can disrupt the body's metabolism, leading to feelings of nausea.⁴

How to lower blood sugar levels

Research has shown that there are various ways to reduce blood sugar levels, as the rise in sugar levels leads to various harmful effects, and many diabetic patients want to avoid blood sugar problems.

  • Insulin: Injection of insulin has been shown to reduce blood sugar levels. The insulin dose is calculated based on the need of the patient.
  • Drinking water: as a high sugar level leads to increased excretion of fluids, water helps rehydration and increases the amount of glucose in the urine.
  • Exercise frequently: Frequent exercise helps you maintain average body weight as obesity is a risk factor for diabetes. Also, exercise increases insulin sensitivity, as the glucose gets mopped up by the insulin.
  • Watch your carbohydrate intake: carbohydrates influence the sugar level of your body. American Diabetes Association (ADA) recommends that people with diabetes watch their carb intake.
  • Take more fibres: Such as vegetables, whole grains, and fruits. These contain complex carbohydrates that cannot be broken down to glucose easily; this helps maintain your glucose level.
  • Monitor blood glucose regularly: Checking your blood glucose levels frequently can help maintain and know when there's a blood glucose spike after meals and if you're doing well on your anti-diabetic medications.
  • Take your drugs and insulin accordingly: Adherence to your medications can go a long way in improving your sugar level, do not miss it and take it as prescribed by your healthcare provider.


In summary, knowing the symptoms of high blood glucose can help you detect early if you are hyperglycaemic and you should report any changes in your body to your health care provider so that proper measures can be put in place.


  1. Hyperglycaemia (High Blood Sugar).” Nhs.Uk, 18 Oct. 2017,
  2. Diabetic Ketoacidosis (DKA): Practice Essentials, Background, Pathophysiology. Oct. 2021. eMedicine,
  3. Diabetes Symptoms: When Diabetes Symptoms Are a Concern.” Mayo Clinic, Accessed 24 Feb. 2022.
  4. January 15, Editor on, et al. “Both Type 1 Diabetes and Type 2 Diabetes Can Cause Nausea or Vomiting in Several Ways.” Diabetes, 15 Jan. 2019,
  5. 14 Easy Ways to Lower Blood Sugar Levels Naturally.” Healthline, 30 Nov. 2021,
  6. Dry mouth and diabetes: Link, symptoms, and treatment [Internet]. 2021 [cited 2022 May 24]. Available from:
  7. Gestational diabetes [Internet]. WebMD. [cited 2022 May 24]. Available from:
  8. Hyperosmolar hyperglycemic nonketotic syndrome(Hhns) [Internet]. Tufts Medical Center Community Care. [cited 2022 May 24]. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Halimat Abdulrasheed

BPharm, Pharmaceutics and Drug, University of Ibadan, Nigeria
She is a content writer, copywriter, and pharmacist. She enjoys writing health contents for blogs etc.

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