Blood sugar level

Synonyms: blood glucose level, blood sugar concentration
German: Blutzucker

1 Definition

The blood sugar level is the concentration of glucose in the blood. The blood sugar level can be specified in mg/dl or mmol/l.

2 Classification

The following parameters can be distinguished depending on the time of measurement relative to food intake:

Alternatively, the HbA_1c derived average glucose level can be used, especially when communicating with the patient.

3 Physiology

Blood glucose concentration is mainly regulated by two antagonistic peptide hormones of the pancreas:

• Insulin decreases blood sugar concentration.
• Glucagon increases it.

Beyond that, catecholamines (adrenaline) and hormones of the adrenal gland (cortisol) effect an increase of blood sugar concentration.

more information: blood sugar regulation

4 Measurement

Blood sugar can be measured either in a laboratory or by the physician, a medical professional or the patient, using a portable blood glucose monitor. Most devices show the results in mg/dl as well as mmol/l. If that isn't the case, the vales can be converted (see below).

see also: blood sugar measurement

5 Reference range

The reference range for fasting blood sugar is

• 60 - 110 mg/dl (corresponds to 3.3 - 6.1 mmol/l)

Blood sugar levels below the reference range indicate hypoglycemia, blood sugar levels above it indicate hyperglycemia.

5.1 Impaired fasting glucose

The following blood sugar values indicate impaired fasting glucose (IFG):

• Fasting blood sugar: between 6.1 and 6.9 mmol/l (110-125 mg/dl)
• 2-hour blood sugar: < 7.8 mmol/l (140 mg/dl)

5.2 Impaired glucose tolerance

Impaired glucose tolerance (IGT) corresponds to the following values:

• Fasting blood sugar: < 7.0 mmol/l (126 mg/dl)
• 2-hour blood sugar: between 7.8 and 11.1 mmol/l (140-200 mg/dl)

5.3 Manifest diabetes mellitus

The following values are a diagnostic criterion for manifest diabetes mellitus:

• Fasting blood sugar: > 7.0 mmol/l (126 mg/dl)
• 2-hour blood sugar: > 11.1 mmol/l (200 mg/dl).

6 Conversion

To convert mg/dl into mmol/l (and vice versa) enter the desired amount and click the red button.

7 Interpretation

Increased blood sugar levels are a symptom of:

• Diabetes mellitus
• Cushing syndrome

Decreased blood sugar levels are a symptom of:

• Insulinoma
• Overdosage of insulin or oral anti-diabetic medication
• Addison's disease (hypocortisolism)
• Malignant tumor
• Hypopituitarism
• Hepatitis
• Autoimmune insulin syndrome
• Alcohol intoxication
• Malnutrition