Type 1 Diabetes: Risk Factors, Signs & Treatment

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  • 0:07 Diabetes and Risk Factors
  • 2:01 Vocabulary Roots
  • 2:39 Type 1 Diabetes Symptoms
  • 5:03 Diagnosis
  • 6:20 Prognosis and Treatment
  • 8:27 Lesson Summary
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Lesson Transcript
Instructor: Jennifer Szymanski

Jen has taught biology and related fields to students from Kindergarten to University. She has a Master's Degree in Physiology.

Diabetes affects 26 million people (nearly 9% of the population) in the United States. But not all cases of diabetes are the same. The focus of this lesson is type 1 diabetes. We'll learn what it is, why it occurs, and how it affects the body in both the short- and long-term.

Definition and Risk Factors

You hear a lot about diabetes in the news, especially how it's linked to factors like unhealthy lifestyle decisions and obesity. But that is not true of every case of diabetes. Diabetes mellitus type 1, more commonly known as type 1 diabetes, is an autoimmune disease of the pancreas that results in a lack of insulin.

Let's break that down. An autoimmune disease is caused by the response of an overactive immune system. Just like an overactive imagination can see a shadow and think it's the boogeyman, an overactive immune system can mistake a part of its own body for a pathogen and attack it. In the case of type 1 diabetes, the immune system attacks beta cells, which are cells in the pancreas located in the islets of Langerhans.

Beta cells are important because they produce insulin, the protein hormone required to get glucose, or sugar, into your body's cells. A reduced number of beta cells equals a reduced amount of insulin. When your body is insulin-deficient, you begin to experience the symptoms of type 1 diabetes.

Scientists have isolated several possibilities as to why this autoimmune response takes place, including:

  • Genetics - activation of several genes is one possibility as to why someone gets type 1 diabetes
  • Environmental factors, such as where you live (for some reason, people living further from the equator tend to be more afflicted)
  • Dietary factors, such as low vitamin D intake
  • And even viral attack

...but there are no definite answers.


Loss of one of the hormones responsible for regulating glucose levels in the body has a profound effect. Let's take a look at some of the symptoms of type 1 diabetes and why they occur.

Don't be intimidated by the new words in this lesson - they share a lot of common roots. Learn the roots, and you will be able to learn the new words without memorizing them. As an example, poly means many or much. You'll notice that root in a few of the terms we'll be using. Other examples are glu or gly for glucose and uri for urine.

Hyperglycemia, or high concentration of glucose in the blood, is the most well-known symptom of diabetes. Since insulin's job is to help glucose get into cells from the bloodstream, it makes sense that a lack of insulin means that a lot of glucose is going to stay in the bloodstream. Normal fasting glucose is about 100 mg/dL. An elevated value of over 125 mg/dL indicates hyperglycemia.

Polyphagia (literally 'very much eating'), or increased hunger, when coupled with weight loss, is another common symptom of type 1 diabetes. If glucose is unable to get into cells, it can't be metabolized to create the energy necessary for cells to function. In a way, the body's cells are starving to death in a sea of glucose. Since the body senses that energy is low, it triggers the hunger response, causing cravings for food, especially sugary carbohydrates.

The presence of glucose in urine, or glycosuria, is not normal. During the process of filtration in a healthy body, the kidneys are able to reabsorb all of the glucose that passes through them. However, if blood glucose levels are over about 170 mg/dL, the kidneys' reabsorption mechanism becomes overwhelmed by the amount of glucose, and some passes into the urine. Glycosuria is often detected by a qualitative commercial dipstick test, where a change in color indicates how much glucose is present.

Polyuria and polydipsia are the increased need to urinate and increased need to drink, respectively. High concentrations of the solute glucose in a diabetic's urine cause water to leave blood plasma and enter the urine through osmosis. This leads to polyuria (literally 'much urine') and results in a frequent need to urinate. In order to make up for this loss of water from the blood, the body's thirst response is triggered, causing polydipsia, the need to drink frequently.


It's vital to note that no one standalone symptom or value can lead to a definitive diagnosis of type 1 diabetes. Let's look at the things we just discussed and how they might lead a medical professional to suspect a case of type 1 diabetes.

  • Age: Usually the autoimmune response responsible for beta cell destruction takes place early in childhood or early adulthood, which is why it used to be called juvenile diabetes. However, type 1 diabetes can also develop in adults, so this term is no longer used.
  • Hyperglycemia coupled with frequent hunger (polyphagia), frequent thirst (polydipsia), and frequent urination (polyuria)
  • Polyphagia
  • Polydipsia
  • Polyuria
  • Autoantibodies for beta islet cells

If these things are all concurrent, a patient should be tested for the presence of autoantibodies, chemical markers that show the immune system has attacked the islet beta cells in order to distinguish between type 1 and type 2 diabetes. Because type 1 diabetes is not caused by unhealthy lifestyle choices and obesity, it is much less common than type 2 diabetes.

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