Blood glucose: what is the normal level and when should you worry?

Verified on 12/28/2023 by Alexane Flament, Editor
Glycémie : quel est le taux normal et quand s'inquiéter ?

Glycemia refers to the level of sugar, called glucose, present in the blood, an essential nutrient for the body’s energy production.

In a healthy person, glycemia is naturally regulated by various hormones present in the body.

Insulin, for example, is a hormone secreted by the pancreas, whose function is to lower blood sugar levels.

Adrenalin, on the other hand, increases blood glucose levels. Other factors, such as diet, physical activity and even stress, can also influence fluctuations in blood glucose levels. Here’s how it works.

When are blood sugar levels considered high?

Hyperglycemia – the medical term for high blood sugar – occurs when blood glucose levels exceed those considered normal.

In practical terms, a high blood sugar level indicates an excessive concentration of sugar in the blood, generally caused by a lack of insulin in the body.

Hyperglycemia presents risks, especially when it persists over long periods.

Under normal conditions and in healthy individuals, blood glucose levels should be between 70 and 99 mg/dL (milligrams per deciliter) on an empty stomach, and remain below 140 mg/dL after a meal.

A concentration below 70 mg/dL indicates hypoglycemia, while a value above 99 mg/dL indicates hyperglycemia.

When should you worry?

Signs of hyperglycemia, such as thirst, fatigue and weight loss, generally appear when blood glucose levels reach a range between 180 and 200 mg/dL.

Although hyperglycemia can affect any individual on a one-off basis, complications arise when this condition persists over time, increasing the risk of diabetes-related complications.

If glucose levels exceed 200 mg/dL, immediate treatment with insulin is required to regulate them.

What’s more, if a person’s blood sugar exceeds 250 mg/dL, it’s imperative to promptly perform a urine test to assess the presence of ketones.