Blodsukker

Blodsukker, or blood sugar, refers to the concentration of glucose in the bloodstream. It is routinely measured in plasma and reported in millimoles per liter (mmol/L) or milligrams per deciliter (mg/dL). In healthy individuals, fasting blodsukker typically falls around 3.9–5.5 mmol/L (70–99 mg/dL). After a meal, levels rise but usually stay below 7.8 mmol/L (140 mg/dL) two hours later.

Glucose balance is regulated mainly by insulin and glucagon, hormones produced by the pancreas. Insulin lowers blodsukker by promoting uptake of glucose into liver, muscle, and fat tissue, while glucagon raises it by stimulating glucose production in the liver. The liver, with contributions from other tissues, maintains glucose through glycogenolysis and gluconeogenesis. Diet, physical activity, stress, and illness can influence blodsukker, which is part of broader energy metabolism.

Abnormal regulation can lead to diabetes or prediabetes. Diabetes includes type 1 (insulin deficiency), type 2 (insulin resistance), and gestational diabetes. Diagnostic criteria commonly include fasting plasma glucose ≥ 7.0 mmol/L (126 mg/dL), a 2‑hour plasma glucose after a 75 g oral glucose load ≥ 11.1 mmol/L (200 mg/dL), or HbA1c ≥ 6.5%. Prediabetic states include impaired fasting glucose and impaired glucose tolerance.

Monitoring is important for management, particularly in diabetes. People may perform self-monitoring of blood glucose (SMBG) with finger-stick tests or use continuous glucose monitoring (CGM). Management combines diet, physical activity, and medications such as metformin or insulin, tailored to the individual.

Chronic hyperglycemia or recurrent hypoglycemia can lead to complications, including vascular damage, neuropathy, kidney disease, eye disease, and cardiovascular issues. Maintaining blodsukker within target ranges reduces these risks.