What Is a Fatal Blood Sugar Level?

Blood sugar levels indicate the amount of sugar or glucose absorbed into the bloodstream. Blood sugar levels that are either too high or too low can cause death. Diabetics and those with certain conditions such as hypoglycemia must maintain their blood sugar levels and monitor them closely.

Normal Range

The normal blood sugar range is 70 to 100. A diabetic can have a level of 60 to 120 and still feel fine.

Fatally High

A fatally high blood sugar level is anything above 550. It's possible for an adult to reach even higher levels before exhibiting any symptoms or problems. When the level reaches 600, the person develops hyperosmolar syndrome, which can cause diabetic coma and death.

Fatally Low

Doctors say that a blood sugar level below 50 is fatal. Levels below 60, even in a healthy person, are potentially fatal, especially if the blood sugar drops quickly.


Not all people experience the same problems from high blood sugar. Some people can have readings ranging up to 800 and have only minimal problems, while others may have symptoms when their levels go above 200.


To combat problems with blood sugar, patients can eat a healthy diet and may need prescribed medication. Some take insulin shots, and others take Glucophage or another type of pill. Experts also recommend exercising and monitoring blood sugar levels for any sudden and frequent drops or peaks.