What Happens Without Enough Insulin

Glucose is sugar in your blood. It is the main fuel your cells use.

Insulin works like a key. It opens cells so glucose can get in.

When there is too little working insulin, fewer cells get opened. Glucose stays in the blood and builds up. Then your cells get less fuel than they need.

Blood sugar that stays high can make you thirsty and tired. It can also send you to the bathroom a lot. Your kidneys filter your blood. When sugar is high, they flush extra glucose out in your urine.

Tell your care team if these signs keep coming back. A very high or very low reading needs prompt medical care.

When cells get less glucose, the body may burn fat for energy. Burning fat can make acids called ketones.

DKA, or diabetic ketoacidosis, is a serious emergency. It means the blood has turned too acidic. Get medical care right away, or call emergency services, if you think DKA is happening.

A cluster of plump yellow fat cells sits on the left, with a short arrow leading to a tall measuring cylinder labelled Ketones. As the fat cells shrink, ketone drops travel along the arrow and the level in the cylinder rises. A ketone test strip beside it turns amber, then red, with a pointer on the matching colour square, and last a phone and an ambulance show getting medical help now.

Key takeaways

• Too little working insulin lets glucose build up in the blood, and the body may burn fat to make ketones.
• Blood sugar that stays high can cause thirst, frequent urination and tiredness.
• Very high or very low blood sugar needs prompt medical attention.

Try it

For three days, note each evening if you felt unusually thirsty, made extra bathroom trips or felt tired. Bring the list to your next visit.