Blood sugar (glucose) is the main fuel for your body. Insulin, a hormone made by the pancreas, helps sugar move from the blood into the cells. Diabetes happens when the body makes too little insulin or can't use it well, so sugar builds up in the blood.

How sugar is tested

  • Fasting blood sugar: after 8 hours without food. Normal is below 5.6 mmol/L; 7.0 or higher suggests diabetes.
  • HbA1c: shows your average sugar over about 3 months. Below 5.7% is normal; 6.5% or higher suggests diabetes.
  • Random blood sugar: any time of day. 11.1 mmol/L or higher with symptoms suggests diabetes.

How high sugar can feel

Many people with type 2 diabetes feel nothing for years. When there are signs, they include thirst, urinating often (also at night), tiredness, blurred vision and wounds that heal slowly. Sugar often rises most in the 1–2 hours after a starchy or sugary meal, and it can be high on waking.

How low sugar can feel

Low sugar (below 3.9 mmol/L) mostly affects people taking insulin or some diabetes tablets. Signs are shaking, sweating, sudden hunger, a fast heartbeat and confusion. Take something sugary, such as half a glass of juice, and check again after 15 minutes. If the person cannot swallow or is unconscious, get emergency help.

What helps

  • Cut sugary drinks first
  • Fill half the plate with vegetables and keep starch portions smaller
  • Walk for 10–15 minutes after meals
  • Take medicines exactly as prescribed and never change doses on your own

Want your numbers checked?

Visit a VitalPoint clinic for a 5-minute check and a personal report on WhatsApp.

Find a clinic

This page is general health education and does not replace advice from a doctor or health worker.