Type 2 Diabetes Symptoms & Causes

Because our research informs our treatment, our diabetes team is known for our innovative treatments and science-driven approach. Boston Children's Hospital is home to the world’s most extensive pediatric hospital research enterprise, and we partner with elite health care and biotech organizations around the globe. But as specialists in family-centered care, our physicians never forget that your child is precious, and not just a patient.

In dealing with your child’s diabetes, you probably want to know the basics about what diabetes is, and how type 2 diabetes differs from other forms of the disease.

What are the major forms of diabetes?

Diabetes (diabetes mellitus) is a lifelong condition that occurs when the body doesn’t make enough insulin, or when the body doesn’t respond properly to the insulin it makes. There are many forms of diabetes mellitus, several of which have undergone name changes as the disease has become better understood.

  • type 2 diabetes: Formerly known as “adult onset” or “non-insulin dependent” diabetes, type 2 diabetes typically occurs in people who are overweight, physically inactive and over age 40, although more and more children are developing type 2 diabetes, possibly because of childhood obesity. Some children need insulin; others can control their diabetes with healthful eating and exercise, or oral medicines (hypoglycemic agents).
  • type 1 diabetes: Formerly known as “juvenile” or “insulin-dependent” diabetes, type 1 diabetes is caused by the immune system’s failure to recognize the beta cells as belonging to the body, so it attacks and destroys them. This is why type 1 diabetes is considered an autoimmune disease. Children with type 1 diabetes must take insulin injections every day.
  • maturity onset diabetes of youth (MODY): The main feature of MODY is that diabetes has been diagnosed before the age of 35 years in at least three generations of family members. Doctors have identified many specific genetic defects (mutations) in such families. Some people who have MODY need insulin. Others can effectively manage their condition with diet and/or oral medicines. MODY is increasingly being seen in children.
  • secondary diabetes: This is a form of the disease in which the beta cells are destroyed, not by the body’s immune system, but rather by cystic fibrosis, pancreatic surgery or another cause.

Note: diabetes insipidus is a very different condition from diabetes mellitus.

What is insulin?
Insulin is the hormone that allows glucose to enter the cells of the body to provide fuel in the form of glucose. Without insulin, glucose builds up in the bloodstream, starving the body’s cells of energy. Some children with type 2 diabetes need insulin injections. Others can manage their condition with diet, exercise and medication.

  • Insulin is a protein hormone made by the beta cells of an area of the pancreas (an organ that lies behind the stomach).
  • Insulin is needed to help glucose (sugar) enter the cells of the body.
    • When glucose enters the cells, it can be used to produce energy, or it can be stored in the liver and muscles (as glycogen) for later use.
  • Fatty tissue increases the body’s resistance to its own insulin—this is why obesity is the major reason for children or teens to develop type 2 diabetes.
  • If the body becomes resistant to its natural insulin, the insulin must be injected so the body can function properly.
  • Insulin can’t be taken by mouth because the digestive system would destroy it.
  • Human insulin is the kind most commonly used today to treat diabetes. It’s made in special bacteria (by genetic engineering) so that it’s identical to the insulin the human body produces.

What are the risk factors associated with type 2 diabetes?

The major risk factors for type 2 diabetes include:

  • being overweight (Body Mass Index [BMI] >= 85th percentile)

  • age (incidence increases with age)

  • family history of type 2 diabetes

  • lack of regular exercise

  • being a member of certain racial and ethnic groups, such as African-Americans, Hispanics, and Native Americans, Asians and Pacific Islanders

  • conditions associated with insulin resistance, such as:

    • abnormal cholesterol
    • high blood pressure

Children considered to be at risk for type 2 diabetes should be tested periodically, regardless of whether they show signs or symptoms. (For details on diagnosing type 2 diabetes, see Tests.)

What is pre-diabetes?

Pre-diabetes is a condition in which your child’s blood glucose levels are higher than normal, but not high enough for a diagnosis of diabetes. Having pre-diabetes is a significant risk factor for development of diabetes.

Can my child prevent or delay the onset of type 2 diabetes?

Your child may be able to prevent or delay type 2 diabetes by eliminating or reducing her risk factors—particularly through weight management and increasing exercise. The Type 2 Diabetes Program at Children’s can work with you and your child to develop a plan for this.

What are some complications associated with diabetes?

People with type 2 diabetes can also be at risk for:

  • polycystic ovary syndrome (PCOS)
  • high blood pressure
  • high cholesterol and triglycerides (metabolic syndrome)
  • eventual damage to heart, vessels, nerves, feet skin, eyes, kidneys, gums         

Although type 2 diabetes can cause many different problems, there are several key complications that if uncontrolled, can cause emergencies.

  • (only for patients on insulin) hypoglycemia (low blood sugar)

    • occurs when blood sugar drops too low—so the body doesn’t have the source of energy it needs to function properly

    • if unchecked, can result in a low blood glucose medical emergency with loss of consciousness or seizure

    • can result from:

      • too high an insulin dose
      • a missed meal or snack
      • more physical activity than usual
      • sickness with vomiting and/or diarrhea
  • common signs and symptoms include shakiness, sweating, weakness, blurry vision, rapid heartbeat

  • If your child has signs or symptoms of hypoglycemia, measure her blood glucose level (if possible) and give her 15 grams of a fast-acting carbohydrate such as fruit juice, hard candy or raisins. If the child has lost consciousness, is having a seizure or is unable to take food or fluids by mouth, administer injectable glucagon (a hormone that raises blood sugar) as directed by your diabetes team, or call for medical assistance from your local emergency services (e.g., 911).

  • hyperglycemia (high blood sugar):
    • can be a sign that diabetes is not well controlled
    • caused by build-up of glucose in the bloodstream; possible causes:
      • not enough insulin—glucose can’t enter the body’s cells
      • too much food, wrong kinds of food
      • less physical activity than recommended
      • sickness or stressors
    • Common signs and symptoms include: excessive urination, bedwetting, weight loss, thirst, yeast infections, nausea and vomiting
    • If your child has signs or symptoms of hyperglycemia
      • measure her blood glucose level
      • check her urine or blood for ketones
      • if you should administer a “booster shot” of extra insulin
    • Speak with your diabetes team to discuss a management plan for hyperglycemia. Untreated hyperglycemia and the presence of ketones in the urine or blood could signal a medical emergency called diabetic ketoacidosis.
    • Ketoacidosis develops when the body doesn't have enough insulin and breaks down fats instead of sugar to use for energy. Ketones are produced as part of this process; the body cannot release all of the ketones, which then build up in the blood. Ketoacidosis can be life-threatening and needs immediate treatment. Symptoms include shortness of breath, breath that smells fruity, nausea, vomiting and dehydration.
  • diabetic ketoacidosis (more common in type 1 diabetes, but can occur in type 2):
    • lack of sugar to the cells of the body cause the body to break down fats, releasing toxins (ketones) into the bloodstream faster than the kidneys can get rid of them
    • Diabetic ketoacidosis is a serious condition that requires immediate medical attention; children become very sick; call your doctor if your child has ketones in her blood or urine.