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Diabetes Guide

Written by Ada’s Medical Knowledge Team

Updated on

Diabetes is a set of conditions that affect the way your body absorbs glucose, a type of sugar that comes from the food you eat.

When the processes for taking up glucose are disrupted, it can lead to serious health consequences. If left untreated, it can be fatal.

In 2019, diabetes was the ninth leading cause of death globally.[1] But with the right treatment and lifestyle changes, people with diabetes live happy, healthy lives.

So if you’re looking to learn more about diabetes, you’re reading the right article.

If you think you might have diabetes, try using Ada to find out more about your symptoms.

What is diabetes?

To understand diabetes, it’s helpful to know a little about glucose and your body. So let’s have a recap.

When you digest the food you eat, your body extracts glucose from it. That glucose enters your blood through the lining of your intestines, and once it’s there, it triggers your pancreas to release a hormone called insulin.

Insulin is pumped around your body in blood, interacting with cells, and triggering them to take up glucose. Once the glucose enters the cells, they use it for energy to power many of the processes they carry out. When insulin isn’t present in your blood, or your cells stop interacting with it, the glucose in your blood can’t go anywhere, and the concentration increases.

If your blood glucose levels stay too high for a long time, you will become unwell. This is diabetes.

There are 3 main types of diabetes:[2][3]

  • Type 1 can develop suddenly and more commonly at a younger age.
  • Type 2 is the most common type and tends to develop at an older age.
  • Gestational diabetes occurs when blood glucose levels rise during pregnancy but not enough to reach a diagnostic level. This type of diabetes usually disappears after giving birth.

Without treatment, diabetes can lead to several conditions including:[1]

  • Blindness
  • Kidney failure
  • Heart attacks
  • Stroke
  • A need for lower limb amputation

What causes diabetes?

The different types of diabetes have different causes.

Type 1 diabetes is the result of an autoimmune process. That means the body’s immune system mistakes its own healthy cells for foreign ones, attacking and destroying them.

In the case of type 1 diabetes, the immune system targets the insulin-producing cells of the pancreas, which are called beta cells.[4] Once the beta cells are destroyed, they can’t produce insulin anymore.

Type 2 diabetes is not caused by an autoimmune process. With type 2 diabetes, the pancreas may still produce some insulin, but not enough to reduce blood sugar levels sufficiently.[4] Alternatively, type 2 diabetes can occur when cells in the body stop responding to the presence of insulin, so they do not remove glucose from the blood.[4]

The exact mechanisms for how type 2 diabetes comes about are not entirely understood. However, type 2 diabetes risk factors include:[5]

  • Family history of type 2 diabetes
  • Obesity
  • Low physical activity
  • Unhealthy diet
  • Insulin resistance

Gestational diabetes happens due to the hormonal and physical changes that take place during pregnancy, such as weight gain.[3]

What are the diabetes symptoms?

If you experience any of the following symptoms, you should consult with your doctor and get your blood sugar levels checked.[6]

  • Excess urination
  • Excess thirst
  • Unintentional weight loss
  • Constant hunger
  • Blurry vision
  • Tingling of the hands and feet
  • Fatigue
  • Dry skin
  • Sores that heal slowly
  • More infections than usual

People with type 1 diabetes may also experience nausea, vomiting, and stomach pains.[6] Gestational diabetes patients do not show any symptoms. However, gestational diabetes may increase the risk of complications during pregnancy and delivery.[6]

How do doctors diagnose diabetes and what are the important diabetes blood markers?

Doctors will carry out an initial history and physical examination to find out if symptoms are caused by diabetes. They may then carry out some blood tests to confirm the diagnosis.[7]

These are the main diabetes tests:[7][8]

Hemoglobin A1c (HbA1c)

Hemoglobin A1c measures your average glucose levels over the past 3 months.

  • An HbA1c level of below 5.7% is normal
  • HbA1c 5.7-6.4% is a sign of pre-diabetes
  • HbA1c level of 6.5% or higher indicates diabetes

Fasting plasma glucose (FPG)

This measures your glucose levels after an overnight fast.

  • Levels of 99 mg/dL or lower are normal
  • 100-125 mg/dL is a sign of pre-diabetes
  • 126 mg/dL or higher indicates diabetes

2-hour post-load glucose:

This measures your blood glucose levels after eating 75 g of glucose.

  • The levels are checked at 0, 1, 2, and 3 hours
  • At 2-hours, levels of 200 mg/dL or higher indicate diabetes

Random plasma glucose:

This is a non-fasting test that rapidly assesses glucose levels.

To confirm a diagnosis, the doctor may carry out repeat tests.[8]

From the age of 45, you should be tested for diabetes once a year.[9] If you are at an increased risk, then you should get checked more often.[9]

Gestational diabetes is usually diagnosed during prenatal screening.[10]

Is there a link between diabetes and diet and can I reduce my risk?

People who are overweight or obese are at an increased risk of developing type 2 diabetes.[11] With a healthy diet, you can maintain optimal sugar levels and reduce your risk.[12]

You can try:[13]

  • Choosing high-fiber, low-sugar foods
  • Eating lots of fruit, vegetables, and wholegrain
  • Limiting your intake of foods containing saturated and trans fatty acids

It doesn’t stop at diet. Having an active lifestyle and maintaining a healthy weight will also reduce your risk of developing type 2 diabetes.[13]

There is currently no known way to prevent type 1 diabetes.[14]

How do doctors treat diabetes?

People with type 1 diabetes need to take insulin by injection or pump every day to manage their blood sugar levels.[14]

Most people with type 2 diabetes need to take diabetes medication to help manage the condition. However, to maintain healthy blood sugar levels, diet, exercise, and maintaining a healthy weight are also essential.[15]

Wrap-up

Diabetes is a treatable condition. And you can reduce your chances of developing type 2 diabetes by living a healthy, active life.

Just be sure to get your blood sugars and other diabetes blood markers checked on a regular basis.


  1. World Health Organisation [WHO]. Diabetes Fact Sheet. [10 November 2021].

  2. BMJ (2021). Diabetes. Accessed April 5, 2022.

  3. CDC (2021). What is Diabetes?. Accessed April 5, 2022.

  4. NHS (2019). Diabetes. Accessed April 5, 2022.

  5. Galicia-Garcia U, et al. (2020). Pathophysiology of Type 2 Diabetes Mellitus. Accessed April 5, 2022.

  6. CDC (2021). Diabetes Symptoms. Accessed April 5, 2022.

  7. CDC (2021). Diabetes Tests. Accessed April 5, 2022.

  8. BMJ Best Practice (2022). Type 2 Diabetes Investigations. Accessed April 5, 2022.

  9. AAFP (2016). Diabetes Mellitus: Screening and Diagnosis. Accessed April 5, 2022.

  10. NIH (2017). Tests & Diagnosis for Gestational Diabetes. Accessed April 5, 2022.

  11. CDC (2022). Diabetes Risk Factors. Accessed April 5, 2022.

  12. CDC (2021). Eat Well. Accessed April 5, 2022.

  13. BMJ Best Practice. Type 2 Diabetes in adults, Approach. Accessed April 5, 2022.

  14. CDC (2022). What is Diabetes?. Accessed April 5, 2022.

  15. NHS (2020). Understanding Medicine. Accessed April 5, 2022.

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