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Health Information

Hyperglycaemia (high blood sugar) 


Hyperglycaemia is a clinical symptom indicating blood glucose levels higher than normal, that is, blood glucose levels greater than 250 mg/dl. A normal blood sugar level is less than 100 mg/dl “on an empty stomach” after more than 8 hours of fasting, and a blood sugar level measured with a 75g oral glucose tolerance test is 140 mg/dl or less. Therefore, hyperglycaemia can be defined as the condition of a person in which the “fasting” blood sugar level exceeds 100 mg/dl (abnormal fasting blood sugar level) or the blood sugar level 2 hours after a glucose load exceeds 140 mg/dl (impaired glucose tolerance). In a more precise definition, hyperglycaemia is when a patient has a blood sugar level of 250 mg/dl or higher. High blood sugar levels over a long period of time lead to damage to blood vessels and various organ diseases.  


When a patient diagnosed with type 1 diabetes mellitus complains of symptoms such as nausea, vomiting, abdominal pain or loss of consciousness, or an elderly patient with type 2 diabetes mellitus has persistent thirst, polyuria, weight loss or dehydration along with hyperglycaemia, they are likely to develop complications of diabetes mellitus. If the index of blood sugar levels exceeds the norm, it is necessary to immediately contact a specialist in a medical institution, undergo diagnosis and the necessary treatment. 

The characteristic symptoms of hyperglycaemia are a feeling of intense thirst (polydipsia) and hunger, rapid urination (polyuria), weight loss and others.   


If you suspect high blood sugar levels, you should immediately visit a medical centre and undergo a diagnostic test to determine whether or not you have diabetes mellitus. When measuring blood sugar levels on your own, you should bear in mind that incorrect results may be obtained due to the inaccuracy of the measuring device and the imperfection of the measurement method. For a more accurate measurement of blood sugar levels and a precise diagnosis, venous blood tests are required.  

Treatment and course of the disease

If the patient’s blood sugar level remains above 250 mg/dl for a prolonged period of time, the doctor should look for symptoms such as loss of consciousness or dehydration. However, depending on how serious the condition is and how high the degree of hyperglycaemia is, as well as how quickly the disease is progressing, intensive and immediate treatment of the patient may be required to lower blood sugar levels. It is important to measure and monitor blood sugar levels regularly because even in the absence of obvious symptoms of the disease, high blood sugar levels increase the likelihood of developing chronic disease and the negative effects of diabetes on the eyes, kidneys, heart, nervous and circulatory systems, and blood vessels of the brain.  

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