Diagnosing Carlos who has type 1 diabetes

We would like to introduce you to the first of our patients, Carlos. Carlos is 25 years old, lives in Spain and has type 1 diabetes.

Let us find out some more about Carlos

Initial diagnosis

Carlos was diagnosed with type 1 diabetes when he was 5 years old.

What does this mean?

Carlos describes his memories of being diagnosed…

Carlos describing when he was diagnosed and symptoms

Carlos describing frequent toilet trips and weight loss

Carlos meets doctor with his mother and is diagnosed with type 1 diabetes

Type 1 diabetes is commonly diagnosed in children and adolescents. Carlos developed type 1 diabetes because his own immune system attacked itself (auto-immune damage), and damaged the pancreas, the organ that produces insulin.

Without type 1 diabetes, the pancreas constantly releases insulin to keep glucose levels stable and ‘automatically’ knows to release more when blood glucose levels exceed a certain threshold, such as during a meal (see diagram).

Graph of insulin and blood glucose levels during the day Figure: graph comparing the effect of insulin levels with and without type 1 diabetes on blood glucose levels during the day

The special cells in his pancreas that make insulin are called β cells and they are now damaged so he is not producing any insulin. This means that when Carlos eats, his blood sugar levels rise very high and stay high for a long time, because there is no insulin to reduce the glucose.

Without taking insulin, Carlos is at risk of developing diabetic ketoacidosis (DKA) which can be life threatening (we will be discussing this in week 2 of the course). 


Carlos is slim. This is because without insulin, the body is not very good at laying down fat or muscle.

Carlos continues to describe his memories of what happened after being diagnosed with type 1 diabetes…

Carlos describing how parents had to ensure he was injected with insulin and making sure he ate properly

Carlos describing how his parents might have found it hard and how type 1 diabetes continues to affect him


What do you think are the challenges that Carlos (growing up) and his parents might have faced in daily life?


There are links relating to type 1 diabetes resources available from ‘See also’ at the bottom of this page.

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This article is from the free online course:

Understanding Insulin

University of Southampton