Last Updated on March 17, 2025 by Analgesia team
Diabetes mellitus is the medical term for diabetes, a condition that occurs when the body doesn’t produce enough insulin or respond normally to it. This causes blood sugar levels to rise above normal.
It is diagnosed from a blood test.
There are 2 main types of diabetes: Type 1 and Type 2 Diabetes. However, there are still other types of diabetes that are less common, which include Gestational, Mody, Type 3C, e.t.c
The causes and symptoms depend on the type of diabetes you have.
Diabetes happens because of a problem with a hormone called insulin.
When you eat or drink, any carbohydrate in your food is turned to glucose, a type of sugar. It is the main sugar found in your blood. It is your body’s primary source of energy. Insulin is like a key that unlocks and allows the body cells to take in glucose to give you energy.
If you have diabetes mellitus, the process explained above won’t happen. Rather, sugar builds up in the blood, causing a spike in your blood. Over time, high blood sugar can cause problems in almost every part of your body. So, treatment is about trying to keep your blood sugars within a target range.
Being as active as possible, eating healthily and going for regular health checks will help you manage your diabetes.
Some people will also need to take some insulin or other medications and check their blood sugar regularly.
A lot of things can affect your blood sugar, so it’s a tricky balance.
It is possible to live a fulfilling life. It is all about being in tune with your body and learning what works for you.
Types of Diabetes
There are two main types of diabetes: type 1 and type 2.
Type 1 diabetes mellitus (T1DM)
People with type 1 diabetes do not produce insulin because their immune system (the body’s system for fighting infection) attacks and destroys the insulin-producing beta cells in the pancreas, leaving little or no insulin. Without insulin, sugar builds up in the blood instead of being transferred into the cells.
The cause of type 1 diabetes is not known, but it is thought to be a combination of genetic and environmental factors.
In the UK, type 1 diabetes accounts for approximately 10% of all diabetes cases, with the majority (around 90%) being type 2 diabetes.
It can appear at any age but often develops in children and young adults.
Type 2 diabetes mellitus (T2DM)
Type 2 diabetes occurs when the pancreas does not produce enough insulin or the body cannot use the insulin properly ( a condition known as insulin resistance). T2DM is the most common type of diabetes, and genetic and environmental factors may play a role in its development.
The following factors play an important role in causing high blood sugar and insulin resistance in individuals genetically prone to type 2 diabetes:
- Beta cells in the pancreas slowly stop producing insulin
- Alpha cells in the pancreas produce too much of a hormone called glucagon, which stimulates the liver to make sugar. The body can’t use this sugar, so it is released into the bloodstream.
- The liver fails to store sugar as an energy source
- The kidney overproduces glucose and increases the absorption of glucose into the blood.
- Low insulin levels cause the fat cells to break down and release free fatty acids. These fatty acids(FFAs) cause the liver to make more sugar, destroy the insulin-producing beta cells in the pancreas and block the muscles from using glucose for energy.
- Muscle cells are unable to absorb and use glucose for energy. The unused glucose stays in the blood, spiking the blood sugar.
- Eating releases hormones that tell the pancreas to produce /release insulin, prevent the liver from making sugar, slow the passage of food through the stomach and send the brain a message to feel full. In type 2 diabetes, these hormones are impaired, resulting in weight gain and reduced insulin levels.
Other Types of Diabetes
Many people are familiar with type 1 and type 2 diabetes, but several other types are just as important to recognize:
- Gestational diabetes – This develops during pregnancy and usually goes away after birth, but it increases the risk of type 2 diabetes later in life.
- Type 3c diabetes – This is caused by damage to the pancreas from conditions like pancreatitis, pancreatic cancer, or surgery.
- Matuity-Onset Diabetes of the Young (MODY) is a rare, inherited form of diabetes caused by a genetic mutation.
- LADA (Latent Autoimmune Diabetes in Adults) – Sometimes called type 1.5 diabetes, LADA develops in adulthood and has characteristics of both type 1 and type 2 diabetes.
Since all types of diabetes lead to high blood sugar levels, they can cause similar symptoms such as increased thirst, frequent urination, fatigue, and blurred vision. Managing blood glucose levels is key to preventing complications.
Causes of Diabetes Mellitus
The causes of diabetes depend on the type, but all forms result in high blood sugar (glucose) due to problems with insulin production or use. Here’s a breakdown of the main causes:
1. Type 1 Diabetes
- Type 1 diabetes is an autoimmune reaction where the immune system attacks insulin-producing cells in the pancreas.
- The exact cause is unknown, but genetic and environmental factors (like viral infections) may trigger it.
- The body produces little or no insulin, requiring lifelong insulin therapy.
2. Type 2 Diabetes
- The body becomes resistant to insulin, or the pancreas doesn’t make enough insulin.
- Linked to lifestyle factors like obesity, poor diet, lack of exercise, and genetics.
- More common in adults but is increasingly seen in younger people.
3. Gestational Diabetes
- Develops during pregnancy when hormonal changes make the body resistant to insulin.
- The pancreas may not produce enough insulin to compensate.
- Usually goes away after birth but increases the risk of developing type 2 diabetes later.
4. Type 3c Diabetes
- Caused by damage to the pancreas from conditions like pancreatitis, pancreatic cancer, or surgery.
- The damaged pancreas can’t produce enough insulin.
5. MODY (Maturity-Onset Diabetes of the Young)
- A rare genetic form of diabetes caused by a mutation in a single gene.
- Often misdiagnosed as type 1 or type 2 diabetes.
6. LADA (Latent Autoimmune Diabetes in Adults)
- A slow-developing form of autoimmune diabetes that occurs in adults.
- Often misdiagnosed as type 2 diabetes at first because it develops gradually.
Other factors that may contribute to diabetes include:
- Family history (genetics).
- Autoimmune conditions.
- Obesity and physical inactivity.
- Hormonal imbalances.
- Certain medications (e.g., steroids, antipsychotics)
Symptoms of Diabetes Mellitus
The symptoms of diabetes can vary depending on the type and how high the blood sugar levels are. However, some common symptoms appear in most types of diabetes.
- Increased thirst (polydipsia) – Feeling very thirsty all the time.
- Frequent urination (polyuria) – Needing to urinate more often, especially at night.
- Extreme hunger (polyphagia) – Feeling constantly hungry, even after eating.
- Unexplained weight loss – Losing weight without trying, more common in type 1 diabetes.
- Fatigue – Feeling tired and weak due to the body not getting enough glucose for energy.
- Blurred vision – High blood sugar can affect the eyes, causing vision problems.
- Slow healing wounds – Cuts and sores take longer to heal than usual.
- Frequent infections – Increased risk of infections, such as skin infections, urinary tract infections (UTIs), and gum infections.
- Tingling or numbness in hands and feet – A sign of nerve damage (diabetic neuropathy), more common in long-term diabetes.
- Dark patches of skin (Acanthosis Nigricans) – Dark, velvety skin patches, usually around the neck or armpits, often a sign of insulin resistance.
Symptoms Specific to Certain Types:
- Type 1 Diabetes: Symptoms develop quickly over days or weeks and may include nausea, vomiting, and severe tiredness.
- Type 2 Diabetes: Symptoms develop gradually and may go unnoticed for years.
- Gestational Diabetes: Usually has no noticeable symptoms but may be detected during routine pregnancy screenings.
If you or someone you know experiences these symptoms, it’s important to see a doctor for testing and diagnosis.
How is diabetes diagnosed?
Diabetes is diagnosed through various blood tests that measure blood sugar (glucose) levels. These tests help determine whether a person has diabetes, prediabetes, or normal blood sugar levels. Below are the key diagnostic tests:
1. A1C (Glycated Hemoglobin) Blood Test
✅ What it measures: The average blood sugar levels over the past 2–3 months.
✅ How it works: This test measures the percentage of hemoglobin (a protein in red blood cells) coated with sugar (glycated hemoglobin).
✅ Is fasting required? No, it can be done at any time of the day.
✅ Results:
- Below 5.7% – Normal
- 5.7% to 6.4% – Prediabetes
- 6.5% or higher – Diabetes
📌 Note: This test may not be accurate for people with anemia or other blood disorders.
2. Fasting Plasma Glucose (FPG) Test
✅ What it measures: Blood sugar levels after an overnight fast (at least 8 hours).
✅ Is fasting required? Yes, you cannot eat or drink anything except water before the test.
✅ Results:
- Below 100 mg/dL (5.6 mmol/L) – Normal
- 100–125 mg/dL (5.6–6.9 mmol/L) – Prediabetes
- 126 mg/dL (7.0 mmol/L) or higher – Diabetes (confirmed with a repeat test)
📌 Note: This test is commonly used for diagnosing diabetes but may not detect all cases.
3. 2-Hour Oral Glucose Tolerance Test (OGTT)
✅ What it measures: How the body processes sugar over time.
✅ How it works:
- The patient fasts overnight.
- A fasting blood sample is taken.
- The patient drinks a sugary solution (75g of glucose).
- Blood sugar levels are tested 2 hours later.
✅ Is fasting required? Yes, at least 8 hours before the test.
✅ Results:
- Below 140 mg/dL (7.8 mmol/L) – Normal
- 140–199 mg/dL (7.8–11.0 mmol/L) – Prediabetes
- 200 mg/dL (11.1 mmol/L) or higher – Diabetes
📌 Note: This test is more commonly used to diagnose gestational diabetes or when FPG/A1C results are inconclusive.
4. Random Plasma Glucose (RPG) Test
✅ What it measures: Blood sugar at any time of the day, regardless of fasting.
✅ Is fasting required? No, it can be done anytime.
✅ Result:
- 200 mg/dL (11.1 mmol/L) or higher, along with symptoms of diabetes (such as frequent urination, thirst, and unexplained weight loss), suggests diabetes.
📌 Note: This test is mainly used for emergency diabetes diagnosis, especially when symptoms are present.
5. Gestational Diabetes Tests (For Pregnant Women)
Pregnant women are usually tested for diabetes between 24 and 28 weeks of pregnancy using one of the following:
Glucose Challenge Test (Screening Test)
- The patient drinks a 50g glucose solution, and blood sugar is tested after 1 hour.
- If the result is 140 mg/dL (7.8 mmol/L) or higher, a 3-hour OGTT is required for confirmation.
3-Hour Oral Glucose Tolerance Test (OGTT)
- The patient drinks a 100g glucose solution and has blood sugar tested at fasting, 1 hour, 2 hours, and 3 hours.
- If two or more readings are higher than normal, gestational diabetes is diagnosed.
Confirming a Diabetes Mellitus Diagnosis
- If a test result suggests diabetes, the doctor usually repeats the test on a different day to confirm.
- If a person has symptoms of diabetes plus a random blood glucose of 200 mg/dL or higher, a second test may not be needed.
Managing Your Diabetes Mellitus
Once diagnosed, managing diabetes is essential to maintaining healthy blood sugar levels and preventing complications. Management strategies depend on the type of diabetes, but they generally include lifestyle changes, medications, and regular monitoring.
1. Lifestyle Changes for Diabetes Management
a) Healthy Eating (Diabetes Diet)
🍎 Focus on:
✔ Whole grains (brown rice, whole wheat, quinoa)
✔ Lean proteins (chicken, fish, tofu, beans)
✔ Healthy fats (nuts, seeds, olive oil, avocados)
✔ Fiber-rich foods (vegetables, fruits, legumes)
🚫 Limit:
❌ Sugary foods & drinks (soda, candy, processed snacks)
❌ Refined carbs (white bread, white rice, pasta)
❌ Trans fats & saturated fats (fried foods, processed meats)
❌ Excess salt (to control blood pressure)
📌 Tip: Follow the Plate Method – Fill half of your plate with vegetables, one-quarter with protein, and one-quarter with whole grains.
b) Regular Physical Activity
🏃♂️ Benefits:
✔ Lower blood sugar levels
✔ Improves insulin sensitivity
✔ Helps with weight management
✔ Reduces the risk of heart disease
💪 Recommended Exercise:
✅ At least 150 minutes of moderate exercise per week (e.g., brisk walking, cycling, swimming)
✅ Strength training twice a week (e.g., weight lifting, resistance bands)
✅ Simple daily activities (e.g., taking the stairs, walking after meals)
📌 Tip: If on insulin, check blood sugar before and after exercise to prevent low blood sugar (hypoglycemia).
c) Weight Management
⚖ Losing just 5–10% of body weight can significantly improve blood sugar control in type 2 diabetes.
✔ A combination of diet + exercise works best.
📌 Tip: Set realistic goals and make gradual lifestyle changes.
2. Monitoring Blood Sugar Levels
📊 Why is it important?
- Helps track how food, exercise, and medications affect blood sugar.
- Prevents complications like hypoglycemia (low blood sugar) and hyperglycemia (high blood sugar).
🩸 Methods:
✅ Self-Monitoring Blood Glucose (SMBG) – Using a glucometer to check blood sugar levels daily.
✅ Continuous Glucose Monitoring (CGM) – A sensor worn under the skin that tracks glucose levels in real time.
✅ A1C Test (Every 3–6 months) – Measures average blood sugar over the past 2–3 months. Goal: Below 7% for most people.
📌 Target Blood Sugar Levels (General Guide):
| Time | Normal Range | Diabetes Target |
|---|---|---|
| Fasting (before meals) | 70–99 mg/dL | 80–130 mg/dL |
| 2 hours after meals | Below 140 mg/dL | Below 180 mg/dL |
📌 Tip: Keep a blood sugar log to discuss with your doctor.
3. Medications & Insulin Therapy
Depending on the type of diabetes, different medications may be needed.
a) Type 1 Diabetes
💉 Requires insulin for life
- Types of Insulin:
✔ Rapid-acting (before meals)
✔ Long-acting (once/twice daily)
✔ Insulin pumps (continuous insulin delivery)
📌 Tip: Learn how to adjust insulin doses based on meals and activity.
b) Type 2 Diabetes
💊 Common Medications:
- Metformin – First-line medication; improves insulin sensitivity.
- SGLT2 inhibitors (e.g., Jardiance, Invokana) – Help remove excess sugar through urine.
- GLP-1 receptor agonists (e.g., Ozempic, Trulicity) – Slow digestion & lower blood sugar.
- Sulfonylureas (e.g., Glipizide, Glyburide) – Stimulate insulin production.
📌 Tip: Some people with type 2 diabetes may eventually need insulin.
c) Gestational Diabetes
- Managed with diet & exercise first
- Insulin may be required if blood sugar remains high
📌 Tip: Women with gestational diabetes should be screened for type 2 diabetes after pregnancy.
4. Preventing Diabetes Complications
Keeping blood sugar, blood pressure, and cholesterol under control helps prevent complications such as:
🫀 Heart Disease & Stroke – Maintain healthy cholesterol & blood pressure.
👁 Diabetic Retinopathy (Eye Damage) – Get regular eye exams.
🦶 Diabetic Neuropathy (Nerve Damage) – Check feet daily for cuts, sores, or infections.
🩸 Kidney Disease – Monitor kidney function with urine and blood tests.
📌 Tip: Quit smoking, limit alcohol, and manage stress for better health.
5. Emotional & Mental Well-Being
📌 Living with diabetes can be challenging, so managing stress and mental health is important.
🧘♂️ Ways to Cope:
✔ Join a diabetes support group
✔ Practice meditation & relaxation techniques
✔ Talk to a diabetes educator or counselor if feeling overwhelmed
Final Thoughts
✅ Diabetes is manageable with the right approach!
💙 Eat healthy, stay active, take medications as prescribed, and monitor blood sugar regularly.
📌 Work closely with your doctor to create a personalized diabetes care plan.