Signs and Symptoms of Diabetes

There are a number of early symptoms that suggest a child might have type 1 diabetes.

Early symptoms
Mother comforting daughter in bed Mother comforting daughter in bed

  • frequent peeing (urination) in large amounts (polyuria)
  • increase in thirst (polydipsia)
  • dry mouth or throat
  • weight loss
  • increase in appetite (polyphagia)
  • feeling tired or weak

Other symptoms in toddlers or infants

  • diaper rash that doesn’t improve with medicated cream

More serious symptoms

These symptoms appear if the diabetes is not treated, or in some cases when it is undiagnosed.

  • weight loss
  • stomach aches
  • nausea and vomiting
  • heavy, rapid breathing (Kussmaul breathing)
  • drowsiness

What happens in children who aren’t making or taking any insulin?

As the child with diabetes eats, the food is broken down and sugar is still released during digestion. This sugar is absorbed into the bloodstream and is carried to the cells. But the pancreas doesn’t respond by making insulin, so the sugar can’t move into the cells. When the sugar remains locked out of the cells, a chain of events is set in motion. The child may become tired, because the cells are literally starved for energy. Meanwhile, sugar continues to build up in the blood. If this were allowed to continue, the blood would eventually become so thick and syrupy that it wouldn’t flow through the veins. Fortunately, the kidneys do their job. They filter blood and get rid of substances that might otherwise harm the body.

High sugar levels and the kidneys

When the kidneys sense a high level of sugar in the blood, they start getting rid of it through the urine. The point at which the kidneys allow sugar to enter the urine is called the renal threshold.

  • When this excess sugar is eliminated, it also takes the water in which it is dissolved. As a result, the child urinates more often and in larger amounts just to get rid of the sugar. This is called polyuria.
  • The higher the blood sugar level, the more often the child urinates. This often leads to dehydration, so the body demands more water, and the child becomes increasingly thirsty. This is called polydipsia.

Children may complain of a dry sticky mouth or sore dry throat. Parents report children gulping down jugs of juice and large quantities of milk or water. Sometimes parents think their child is urinating so much because of the extra drinking, so they try to cut off the fluids. But the child will continue to urinate often, because the body’s priority is to clear out the excess sugar. Drinking all this fluid is the only way to avoid dehydration.

Excessive urination and thirst are usually the first indications of the high blood sugar (hyperglycemia) of diabetes. Some children have to get up in the middle of the night to go to the bathroom (nocturia). Younger children may even start wetting the bed (enuresis)​. The loss of sugar in the urine, together with dehydration and the inability to use blood sugar, can lead to weight loss despite an increase in appetite (polyphagia). As the symptoms develop, children often feel tired, drowsy, and weak.

Symptoms in infants and toddlers

Early symptoms may not be as clear in infants and toddlers. It’s difficult to recognize thirst in young children who cannot speak. Regular growth spurts can also bring changes in appetite. In these cases, children may quickly progress to more serious symptoms before diabetes is recognized. One additional symptom found in those wearing diapers may be a fungal or yeast diaper rash that doesn’t improve with the use of medicated cream. The fungus or yeast flourishes in the sugar excreted in the urine. In older girls, yeast infections (for example, vaginal discharge or itching) may also be a symptom.

Using fat for energy (more advanced symptoms)

The body needs energy to survive. When the pancreas doesn’t make insulin or the insulin isn’t working, cells don’t get energy. Over time, the body starts to break down fat and proteins to be used as energy. When this happens, there is weight loss. In this process, the body also makes a potentially poisonous byproduct called ketones, or acetone. This is the same chemical used in nail polish remover.

As soon as ketones are made, the kidneys recognize that they are poisonous and filter them out through the urine. If the body can’t filter out the ketones as fast as they are being made, they begin to build up in the blood. This leads to symptoms such as stomach aches and severe nausea. This buildup of ketones is called diabetic ketoacidosis (DKA). When the body can’t get rid of all the ketones through the urine, it can even start exhaling them, so that a fruity or unnatural smell may be noticeable on the child’s breath. Heavy, rapid breathing is one way the body attempts to get rid of more ketones. This is called Kussmaul breathing.

Ketoacidosis is a serious condition. It can lead to unconsciousness and death. Fortunately, giving intravenous fluid and insulin corrects the situation. In fact, this is the sickest most children with diabetes will ever be. Once a child has been diagnosed with diabetes and the parents gain the tools and support they need to manage the disorder, diabetic ketoacidosis should be totally avoidable.

Today, diabetes is most often diagnosed before DKA has developed. If a child has classic symptoms of diabetes, this should trigger further testing. ​

Marcia Frank, RN, MHSc, CDE

Denis Daneman, MB, BCh, FRCPC