Fasting Glucose

When you eat carbs, your gut releases glucose, a type of sugar, into your blood. Your pancreas answers with insulin, a hormone that moves that sugar into cells to burn for energy or tuck away for later.

Overnight, two hormones hold the line. Insulin keeps the level from drifting high, and glucagon nudges your liver to release a little stored glucose so it does not fall too low. This number creeps up when cells stop responding to insulin and the liver pours out more glucose than you need.

A reading in the optimal range tells you your insulin signaling is working and your body resets to a steady baseline overnight. This number is also one of the most responsive you have. Move more, sleep well, eat whole foods, and it tends to follow.

As it climbs, it is an early signal, and an early one is good news. The stage before type 2 diabetes, called prediabetes, often shows up years ahead and responds strongly to change. Sustained high levels do raise risk for the heart, kidneys, nerves, and eyes, and unusually low readings can point to a liver, hormonal, or medication cause. One value is a clue, not a diagnosis, so read it alongside your HbA1c and other markers and confirm anything unexpected with your clinician.