Information for Participants and Families

What has TEDDY done?
What have you done for TEDDY?

Beginning at 3 months of age, our volunteers have been part of the largest study of type 1 diabetes in the world. Around the world, 8667 children have participated in The Environmental Determinants of Diabetes in the Young (TEDDY) study. TEDDY is an international study funded primarily by the National Institutes of Health to investigate factors that may trigger or protect against type 1 diabetes. Each child in TEDDY was asked to participate because they had an increased risk for type 1 diabetes. TEDDY was designed to follow children in the United States, Sweden, Finland, and Germany from birth to their 15th birthday.

Our amazing TEDDY Junior Scientists and their families have made a great contribution to science. We are very grateful that you have taken part in TEDDY! 

Children at increased risk for type 1 diabetes are also often at risk for celiac and thyroid disease.
Participants in TEDDY were monitored for all three conditions.

Diagnosis Numbers Across TEDDY Centers

Do you know the signs and symptoms of these conditions?

Be familiar with the signs and symptoms of type 1 diabetes.

Symptoms include:

  • Excessive thirst
  • No energy (tiredness)
  • Increased urination
  • Weight loss

If you observe any of these symptoms, it is important to seek immediate health care assistance. Early treatment of type 1 diabetes may prevent a severe illness called diabetic ketoacidosis.


Celiac disease is an autoimmune disease. It causes an immune reaction in the intestine when gluten is consumed. Gluten is a protein found in wheat, barley and rye. Celiac disease causes damage to the small intestine resulting in poor absorption of nutrients.

Common symptoms of celiac disease may include gastrointestinal complaints, such as chronic constipation or frequent loose stools. These symptoms may be associated with other illnesses. 

Symptoms of hypothyroidism (low thyroid) can be subtle and may include the following. These symptoms may also be associated with other illnesses.

  • Enlargement of the thyroid gland (goiter)
  • Tiredness
  • Impaired school performance
  • Poor growth
  • Dry skin
  • Constipation
  • Cold intolerance
  • Menstrual irregularities
  • Hair loss

Symptoms of hyperthyroidism (excessive thyroid):

  • Enlargement of the thyroid gland (goiter)
  • Elevated heart rate
  • Trouble sleeping
  • Diarrhea
  • Weight loss
  • Increased appetite
  • Heat intolerance
  • Menstrual irregularities

TEDDY has collected a tremendous variety of samples to help us learn all we can about type 1 diabetes.
This collection has given researchers one of the world's largest and most varied sets of samples to study.
These samples are stored at the NIDDK Repository so TEDDY and other investigators can continue to analyze them and keep learning for many years.
Thank you for all you have contributed!

View the TEDDY Sample Collection Totals