What is Type 1 Diabetes Mellitus?

Dr. Yogesh Yadav

Before going into types of diabetes mellitus let us just briefly see how glucose (sugar) enters our body & how it is used in the body.

Whenever we eat any food item, the carbohydrates (most of the things we eat contain carbohydrates) in it are broken down into simpler forms like glucose and are absorbed. The glucose thus absorbed circulates in our body through blood.

Most of our body organs/cells need glucose to function. Insulin helps glucose to enter these cells from blood.

Insulin is a hormone released from pancreas (an organ near stomach & small intestine)

The glucose (sugar) will keep on circulating in blood if less insulin is available or its function is reduced.

Type 1 diabetes mellitus develops when there is negligible or very low amount of insulin in blood.

Because of lack of insulin, glucose (sugar) is unable to enter into cells and glucose levels in blood go high and the person develops symptoms.

what is type 1 diabetes

Signs and Symptoms

Common symptoms are:

  • Increased frequency of urine (polyuria)
  • Increased thirst (polydipsia)
  • Increased food intake (polyphagia)
  • Weight loss
  • Urinary infection
  • Blurring of vision
  • Generalized weakness

Symptoms may go unnoticed in young kids and only noticeable feature may be night time bed wetting or weight loss despite eating well.

If the symptoms go unrecognized the child may land up in DKA (diabetic ketoacidosis), a serious condition requiring hospital admission with Intensive care unit (ICU) care.


Autoimmune destruction of insulin producing cells in pancreas (called beta type islet cells) is the main cause of type 1 diabetes mellitus.

Autoimmunity is a condition when your own body starts to attack a particular organ/cell in your body.

This leads to almost complete loss of insulin producing cells & hence insulin also. This autoimmunity is caused/modified by various genetic and environmental factors. More than 30 genes have been identified to be associated with type 1 diabetes mellitus.

Common environmental factors include early exposure to cow milk, food containing gluten (e.g. Wheat, barley), certain type of viruses, shorter duration of breast feeding etc.


Diagnosis of type 1 diabetes is done based on high glucose (sugar) levels, symptoms and their duration. Sometimes a child may directly present in emergency with vomiting, dehydration, pain abdomen, labored breathing and is diagnosed as having diabetic ketoacidosis (DKA).

Other tests that are helpful in diagnosis include

  • Antibodies directed against islet cells
  • C-Peptide test


Treatment is in the form of subcutaneous insulin injections along with dietary modifications and exercise. As there is negligible insulin production in the body, these patients usually require 3-5 insulin injections everyday and missing even a single insulin dose may lead to very high sugar levels.

As this disease commonly affects children and adolescents, family support is must. Regular counselling regarding diet, exercise, glucose monitoring, insulin storage and use is also highly recommended