Glucose
Glucose is the sugar in the blood and the body’s main source of energy.
Glucose is the sugar in the blood and the body’s main source of energy. A fasting glucose shows the blood sugar level after a night without food, when insulin and the liver keep it steady. It shows how the body handles sugar at that moment. Retesting shows how it changes over time.
The time since the last meal matters most, which is why the test is taken fasting. Stress, short sleep, a recent cold or infection, hard training shortly before the test and some medicines, such as cortisone, can raise it temporarily. Over time, diet, physical activity and body composition play a role.
Foods that help
Whole grains, legumes and fibre-rich vegetables, together with protein from fish, poultry or eggs and fat from nuts or olive oil, give a steadier blood sugar.
Foods to limit
Sugary drinks, sweets, pastries and white bread make blood sugar rise quickly.
Track it through the year
One value is a snapshot. Following it up shows whether what you changed is working.
Related markers
Educational information only — not a diagnosis. Every result is checked against safe limits, and anything critical is escalated for follow-up.
See all 84 markers →