Causes of Diabetes

The causes of diabetes are not fully understood. However, the causes definitely differ depending on the type of diabetes, whether Type 1 Diabetes or Type 2 Diabetes.

Type 1 diabetes results from the body losing the ability to produce insulin, whereas Type 2 Diabetes usually results from the body losing the ability to use insulin (called “insulin resistance”) even though the body can still produce insulin. However, there is also a less common form of Type 2 Diabetes where the body’s ability to produce insulin is also affected.

The causal factors for each type include:

Secondary Diabetes: It is uncommon for diabetes to have a single clear cause due to another disease, but it can occur. This is called “secondary diabetes” meaning that the diabetes is the “second” disease with another primary (“first”) disease as the original cause. When a person is first diagnosed as having the symptom of hyperglycemia (high blood glucose), there are various other diseases that need to be considered.

Examples of other (primary) diseases that cause secondary diabetes include:

Drug Diabetes: There are a number of drugs and medications that can sometimes cause a form of secondary diabetes or diabetes-like symptoms:

  • Steroids (“steroid diabetes”)
  • Thiazides
  • Furosemide
  • Propranolol
  • Anti-depressants (some types, sometimes)
  • Phenothiazines


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Back to: « Diabetes

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Both aging and obesity can also bring changes to the way your body processes glucose—the sugar your body makes from food and uses for energy. These changes can lead to diabetes, which raises your risk for heart disease, blindness, amputations, and other conditions.

“Obesity increases the risk, and reduces the age of onset, for many diseases of aging,” Mattson says. “Over the long-term, even our brains are affected. Emerging evidence suggests that long-standing diabetes and obesity can lead to changes in brain cells that make them vulnerable to aging.”

Source: NIH News in Health (NIH)1

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What causes diabetes?

The exact causes of diabetes are not fully understood and typically involve multiple factors, such as genetics and interactions with the environment.

The majority of cases of type 1 diabetes are "sporadic" meaning there is no family history of the condition. Likewise, the rates of type 1 diabetes in both members of set of identical twins is lower than would be expected if the condition was caused by genetics alone. The environmental component is strong and could result from a combination of factors, such as exposure to viruses in the small intestine or to foreign proteins from foods at a time when the immune system of the digestive tract is too immature to process them.

Obesity is a major factor in developing type 2 diabetes. More than 80% of Americans with type 2 diabetes are obese or overweight. Obesity lessens the body’s ability to control blood sugar, so the body overproduces insulin to compensate—and a cycle develops.3

Pregnancy causes many different changes to the body, including changes to metabolism that result in gestational diabetes. These changes are usually the result of hormones produced during pregnancy that keep insulin from doing its job.

Source: NICHD (NIH)2

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When you have diabetes, your body either doesn't make enough insulin or can't use its own insulin as well as it should. This causes sugar to build up in your blood.

Source: CDC3

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What else can cause diabetes?

Genetic mutations , other diseases, damage to the pancreas, and certain medicines may also cause diabetes.

Genetic mutations

Hormonal diseases

Some hormonal diseases cause the body to produce too much of certain hormones, which sometimes cause insulin resistance and diabetes.

  • Cushing’s syndrome occurs when the body produces too much cortisol—often called the “stress hormone.”
  • Acromegaly occurs when the body produces too much growth hormone.
  • Hyperthyroidism occurs when the thyroid gland produces too much thyroid hormone.

Damage to or removal of the pancreas

Pancreatitis, pancreatic cancer, and trauma can all harm the beta cells or make them less able to produce insulin, resulting in diabetes. If the damaged pancreas is removed, diabetes will occur due to the loss of the beta cells.

Medicines

Sometimes certain medicines can harm beta cells or disrupt the way insulin works. These include

Statins, which are medicines to reduce LDL (“bad”) cholesterol levels, can slightly increase the chance that you’ll develop diabetes. However, statins help protect you from heart disease and stroke. For this reason, the strong benefits of taking statins outweigh the small chance that you could develop diabetes.

If you take any of these medicines and are concerned about their side effects, talk with your doctor.

Source: NIDDK (NIH)4

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What else can cause diabetes?

Genetic mutations , other diseases, damage to the pancreas, and certain medicines may also cause diabetes.

Genetic mutations

Hormonal diseases

Some hormonal diseases cause the body to produce too much of certain hormones, which sometimes cause insulin resistance and diabetes.

  • Cushing’s syndrome occurs when the body produces too much cortisol—often called the “stress hormone.”
  • Acromegaly occurs when the body produces too much growth hormone.
  • Hyperthyroidism occurs when the thyroid gland produces too much thyroid hormone.

Damage to or removal of the pancreas

Pancreatitis, pancreatic cancer, and trauma can all harm the beta cells or make them less able to produce insulin, resulting in diabetes. If the damaged pancreas is removed, diabetes will occur due to the loss of the beta cells.

Medicines

Sometimes certain medicines can harm beta cells or disrupt the way insulin works. These include

Statins, which are medicines to reduce LDL (“bad”) cholesterol levels, can slightly increase the chance that you’ll develop diabetes. However, statins help protect you from heart disease and stroke. For this reason, the strong benefits of taking statins outweigh the small chance that you could develop diabetes.

If you take any of these medicines and are concerned about their side effects, talk with your doctor.

Source: NIDDK (NIH)5

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What Is Diabetes?

Our bodies turn the food we eat into glucose. Insulin helps glucose get into our cells, where it can be used to make energy. If you have diabetes, your body may not make enough insulin, may not use insulin in the right way, or both. That can cause too much glucose in the blood. Your family doctor may refer you to a doctor who specializes in taking care of people with diabetes, called an endocrinologist.

Source: NIA (NIH)6

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What causes diabetes?

Researchers do not know the exact causes of type 1 and type 2 diabetes. Researchers do know that inheriting certain genes from your family can raise your risk for developing diabetes. Obesity is also a major risk factor for type 2 diabetes. Smoking can also cause type 2 diabetes. And the more you smoke the higher your risk for type 2 diabetes and other serious health problems if you already have diabetes.[13]

Weight loss can help control type 2 diabetes so that you are healthier. Quitting smoking can also help you control your blood sugar levels. Being a healthy weight and not smoking can help all women be healthier.

But, obesity and smoking do not always cause diabetes. Some women who are overweight or obese or smoke never develop diabetes. Also, women who are a normal weight or only slightly overweight can develop diabetes if they have other risk factors, such as a family history of diabetes. 

Source: OWH (DHHS)7

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Causes of diabetes

The amount of sugar in the blood is controlled by a hormone called insulin, which is produced by the pancreas (a gland behind the stomach).

When food is digested and enters your bloodstream, insulin moves glucose out of the blood and into cells, where it's broken down to produce energy.

However, if you have diabetes, your body is unable to break down glucose into energy. This is because there's either not enough insulin to move the glucose, or the insulin produced doesn't work properly.

Although there are no lifestyle changes you can make to lower your risk of type 1 diabetes, type 2 diabetes is often linked to being overweight.

Read about how to reduce your diabetes risk.

Source: NHS Choices UK8

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Pancreatic cancer: You may also develop symptoms of diabetes if you have pancreatic cancer, because it can produce chemicals that interfere with the normal effect of insulin.

Source: NHS Choices UK9

Causes of Diabetes

Causes of the condition may include:10 Causes of Diabetes:

Physiological Causes of Diabetes

What causes diabetes?

Diabetes is a disease of metabolism, which is the way the body uses food for energy and growth.1 In particular, it’s related to one of the food nutrients that supply energy, called carbohydrates.2 Normally, the stomach and intestines digest the carbohydrates in food into a sugar called glucose. Glucose is the body’s main source of energy. After digestion, the glucose moves into the blood to give the body energy.

To get the glucose out of blood and into the body’s cells, the pancreas makes a hormone called insulin. In diabetes, either the body doesn’t make enough insulin, or the cells can’t use it the way they should. Instead, the glucose builds up in the blood, causing diabetes, otherwise known as high blood sugar.

Source: NICHD (NIH)11

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Diabetes means your blood sugar is too high. Diabetes is a disease of metabolism, which is the way your body uses food for energy and growth. Your stomach and intestines break down (or digest) much of the food you eat into a simple sugar called glucose (pronounced GLOO-kos). Glucose is your body's main source of energy.

After digestion, the glucose passes into your bloodstream, which is why glucose is also called blood sugar. This booklet uses the terms glucose and blood sugar to mean the same thing. Once in the blood, the glucose is ready for your body cells to use. But your cells need insulin (pronounced IN-suh-lin), a hormone made by your body, to get the glucose. Insulin "opens" your cells so that glucose can get in. When your metabolism is normal, your body makes enough insulin to move all the glucose smoothly from your bloodstream into your cells.

If you have diabetes, your insulin and glucose levels are out-of-balance. Either your body doesn't make enough insulin, or your cells can't use insulin the way they should. Without insulin, the glucose that can't get into your cells builds up in your bloodstream. This is called high blood sugar or diabetes. After a while, there is so much glucose in the blood that it spills over into your urine and passes out of your body. The medical name for diabetes, diabetes mellitus, means "sweet urine."

Source: NICHD (NIH)12

Causes List for Diabetes

Some of the possible causes of Diabetes or similar disorders may include:13

... Full Causes List for Diabetes »

Genetics of Diabetes

Genes provide the instructions for making proteins within the cell. If a gene has a mutation, the protein may not function properly. Genetic mutations that cause diabetes affect proteins that play a role in the ability of the body to ...14

... More on Genetics »

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References

  1. Source: NIH News in Health (NIH): newsinhealth.nih.gov/ issue/ jul2015/ feature2
  2. Source: NICHD (NIH): nichd.nih.gov/ health/ topics/ diabetes/ conditioninfo/ Pages/ causes.aspx
  3. Source: CDC: cdc.gov/ diabetes/ basics/ diabetes.html
  4. Source: NIDDK (NIH): niddk.nih.gov/ health-information/ diabetes/ overview/ symptoms-causes
  5. ibid.
  6. Source: NIA (NIH): nia.nih.gov/ health/ diabetes-older-people
  7. Source: OWH (DHHS): womenshealth.gov/ a-z-topics/ diabetes
  8. Source: NHS Choices UK: nhs.uk/ conditions/ Diabetes/ 
  9. Source: NHS Choices UK: nhs.uk/ conditions/ pancreatic-cancer/ 
  10. Source: Human Phenotype Ontology
  11. Source: NICHD (NIH): nichd.nih.gov/ health/ topics/ diabetes/ conditioninfo/ Pages/ causes.aspx
  12. Source: NICHD (NIH): nichd.nih.gov/ publications/ pubs/ gest_diabetes/ Pages/ sub1.aspx
  13. Source: Algorithmically Generated List
  14. Source: NIDDK (NIH): niddk.nih.gov/ health-information/ diabetes/ overview/ what-is-diabetes/ monogenic-neonatal-mellitus-mody

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Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.