Diabetes: hypoglycaemia, hyperglycaemia and ketoacidosis - everything you need to know!

Published 22 Apr 2022 • By Candice Salomé

In people with diabetes, insulin production is deficient or non-existent. This leads to abnormal variations in blood sugar levels. When the amount of sugar in the blood is too high, it is called hyperglycaemia. Conversely, when the amount of sugar in the blood is too low, it is called hypoglycaemia. Ketoacidosis is an increase in blood acidity due to an insufficient dose of insulin, compared to the patient's needs.

So what are the symptoms of hypoglycaemia, hyperglycaemia and ketoacidosis? What should you do in you are affected? 

We explain it all in our article!

Diabetes: hypoglycaemia, hyperglycaemia and ketoacidosis - everything you need to know!

What is hypoglycaemia and what are its symptoms? 


Hypoglycaemia means that blood sugar levels are too low, i.e. below 0.7 g/L.

Hypoglycaemia occurs mainly in people who are being treated with such medications as sulphonamides, glinides and insulin. These can cause blood sugar levels to drop too low.

However, a sudden drop in blood sugar levels can also occur in other circumstances.

For example, medication doses may become inappropriate as the disease progresses. 

But hypoglycaemia may also occur in situations which are more related to lifestyle changes

For example:

  • A change in eating habits. Indeed, skipping meals, eating later than usual or eating a meal that is lighter than usual or does not contain enough starch, could lead to hypoglycaemia,
  • Increased or unplanned physical activity can also lead to hypoglycaemia,
  • Taking a non-diabetic medication that lowers blood glucose levels,
  • A change in diabetes treatment,
  • A mistake in the dosage of insulin or other diabetes medication,
  • Or drinking certain types of alcohol such as whisky, gin or vodka.


Symptoms of hypoglycaemia may include:

  • Sweating, mild nausea, paleness, abnormal hunger,
  • Nervousness, palpitations, irritability or trembling,
  • Tingling or pins and needles in the area around the mouth,
  • Headache, blurred vision, dizziness,
  • Loss of balance, feeling weak,
  • A feeling of anxiety and increased heart rate.

All of these symptoms may become worse and lead to lack of concentration, difficulty speaking, confusion, muscle twitching or mood disorders. In rarer cases, hypoglycaemia can cause seizures or loss of consciousness.

What to do? 

In the event of hypoglycaemia, you should :

  • Quickly eat something that contains sugar: it should be an equivalent of 15 grams, or 3 lumps of white sugar. Be careful not to eat too much sugar too quickly, as this can lead to hyperglycaemia. Eating fast-acting carbohydrates (such as limps of sugar or sweets) can be followed by a meal of slow-release carbohydrates, in order to restore blood sugar levels in the long term,
  • Sit or lie down for a few minutes.

If the patient has a blood glucose meter, self-monitoring allows him/her to confirm (or not) an episode of hypoglycaemia and thus to be able to monitor its evolution.

If you do not notice any improvement or if you do not know what to do in case of hypoglycaemia, contact your doctor as quickly as possible. In some cases, your doctor may prescribe medication (glucagon) in the form of injection, to be administered by someone close to you, if hypoglycaemia persists despite a sufficient intake of carbohydrates.

If the situation worsens, call 999 immediately

In addition, it is highly recommended that you always carry with you a list of all the treatments you are taking.

What is hyperglycaemia and what are its symptoms? 


Certain situations can cause an increase in blood sugar levels even when diabetes is well controlled. These are called hyperglycaemic episodes, and are characterised by fasting blood sugar levels being greater than or equal to 1.10 g/L.

Hyperglycaemia can occur in the following situations:

  • Missing your insulin injection or taking medication irregularly,
  • Contracting an infection,
  • Taking medication that increases blood sugar levels,
  • Suffering from severe stress.


If hyperglycaemia is significant, the body will try to eliminate the excess of sugar.

The manifestations of hyperglycaemia are as follows:

  • More urgent need to urinate,
  • An increase in the amount of urine, that can cause a significant loss of water, which in its turn can lead to dehydration. Dehydration results in severe thirst, dry mouth, sometimes even blurred vision or severe fatigue.

These symptoms can appear quickly or develop for several days.

In some more serious cases, patients may suffer from impaired consciousness which can sometimes progress to coma.

What to do? 

In the event of hyperglycaemia, you need to drink enough to compensate for the loss of water. It is essential to drink water and not sugary drinks.

If your blood sugar level is still high or too high, or if you are not sure what to do in the event of a hyperglycaemic episode, contact your doctor.

If you have a blood glucose meter, it is recommended that you perform several self-monitoring tests. This will allow you to confirm high blood sugar level and monitor its progress.

If the situation seems to be getting worse, call 999.

If you have experienced one or more episodes of hyperglycaemia, it is important to tell your doctor about it. Make a note of the symptoms you have had and the circumstances in which these episodes have occurred, as well as of any questions you may want to ask your doctor.

What is ketoacidosis and what are its symptoms? 


Each diabetic has his or her own treatment, adapted to his or her daily life.

In the case of type 1 diabetes, ketoacidosis is the result of an insufficient dose of insulin, compared to the patient's needs. The body will then use fat to make the energy it needs, producing ketone bodies, which are harmful.

In type 2 diabetes, ketoacidosis is less common and occurs when a disease, treatment or surgery disrupts the blood sugar balance.


The symptoms of ketoacidosis appear gradually:

  • Intense thirst,
  • Frequent urination,
  • Blurred vision,
  • Abnormal fatigue,
  • Loss of appetite,
  • Digestive problems such as abdominal pain or nausea,
  • "Fruity" breath (a smell of apple),
  • Night cramps,
  • Respiratory discomfort,

If left untreated, the patient's condition worsens, and breathing difficulties may occur. Finally, diabetic ketoacidosis may lead to consciousness disorders, which may progress to coma or even death.

What to do?

Teaching the patient to self-monitor their blood glucose levels is essential in order to be able to identify the onset of diabetic ketoacidosis as early as possible. When blood glucose levels are abnormally high (i.e. above 2.5 g/L of blood), a diabetic patient should do routine tests for the presence of ketones in the urine (using urine strips) or in the blood.

Patients with diabetic ketoacidosis are admitted to hospital.

Treatment consists of insulin, saline with glucose and potassium. Afterwards, blood glucose levels and the absence of glucose and ketones in the urine are regularly monitored. Prevention of ketoacidosis is based on the patient's adherence to insulin therapy, in order to control diabetes (without missing the doses).

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       Take care!   

avatar Candice Salomé

Author: Candice Salomé, Health Writer

Candice is a content creator at Carenity and specialises in writing health articles. She has a particular interest in the fields of women's health, well-being and sport. 

Candice holds a master's degree in... >> Learn more

Who reviewed it: Alizé Vives, Pharmacist, Data Scientist

Alizé holds a PharmD and a master's degree in strategy and international business from ESSEC Business School in France. She has several years of experience working with patients and members, conducting surveys for... >> Learn more


Courtney_J • Community manager
on 27/04/2022

Hello everyone,

Have you ever experienced any of these complications of diabetes? If yes, do not hesitate to share your story with other members: what was it? what led to the complication? how did you cope?

Is there anything you would like to add to the information provided in the article?

I'll tag some of the members here, in case they missed the article 😉

@Panigale @cornet.frampton @Dollyb @PinkladyPinklady1963 @Lardyfats @joeskill @Sharonj159 @Helenj3112 @Marie257 @Chegger @Catherine3 @willia895 @Emjcraig @Kentcarl @Ginnie @gemma2020 @lwsjason5 @Andrew13dawson

Thank you all, take care!

Unregistered member
on 30/04/2022

Many Thanks for another article that gives us 'food for thought'. There is so much that we don't know about our disease that can have such long lasting effects. We have to keep learning and manage our own disease. Good luck.

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