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 as an adult saying I can vaguely remember being diagnosed. I was only five. Picture of a young child drinking with the caption I experienced four weeks of feeling increasingly thirsty.

Carlos as a young child thinking: "Oh no, I need to go again!" and the caption: I went to the toilet much more frequently, was urinating large amounts each time I went and felt really tired.  Carlos as a young child standing on some scales with the caption: I was also losing weight or eating less. It didn't seem to matter how much I was eating.

Carlos meets doctor with his mother with the caption: so my parents dragged me to see the doctor. The doctor says "Well, Carlos, I've measured your blood glucose and found the levels to be really high.  We've also found large amounts of ketones in your urine so as you've only had these symptoms for a short time, you have high blood glucose levels and large amounts of ketones I think you have 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 comparing treated type 1 diabetes where the insulin and glucose and insulin levels both dipping before breakfast, lunch and dinner and both rising after with untreated type 1 diabetes where the glucose level remains high and the insulin level stays at zero. 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 as a young boy with this mother and the caption: When I was young it was up to my parents to ensure that I was regularly injected with insulin which wasn't easy for me and to make sure that I was eating things at the right time.

Carlos as an adult saying "being diagnosed at five, It was my parents responsibility to take the lead in looking after me. My life with type 1 diabetes presents a number of cahllenages which continue to affect me daily." The image is captioned: it must have been difficult for them but I didn't appreciate what was happening then.


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