Diabetes Mellitus (DM) is one of the most common and serious chronic diseases worldwide, affecting hundreds of millions of people. It occurs when the body either does not produce enough insulin (Type 1) or becomes resistant to insulin (Type 2). As a result, glucose builds up in the blood instead of entering cells, leading to hyperglycemia and long-term complications.
The term mellitus means “sweetened with honey,” referring to the presence of sugar in urine, one of the earliest observed signs of the condition. Today, diabetes is understood not just as a metabolic disorder of sugar regulation but as a systemic disease that can affect nearly every organ system.
Pathophysiology Basics of Diabetes Mellitus
To understand diabetes, it is essential to understand the role of insulin and glucose metabolism:
- Insulin acts like a key that opens the door of cells, allowing glucose (sugar) and potassium to move inside where they can be used for energy.
- Glycogen is stored glucose in the liver, released when the body needs energy between meals.
In diabetes, this delicate balance is disrupted:
- Type 1 Diabetes Mellitus (T1DM): The pancreas fails to produce insulin because of an autoimmune process that destroys beta cells.
- Type 2 Diabetes Mellitus (T2DM): The body produces insulin, but the cells fail to respond properly (insulin resistance). Over time, insulin production may also decline.
Types and Causes of Diabetes Mellitus
Type 1 Diabetes (T1DM)
- Cause: Autoimmune destruction of pancreatic beta cells.
- Onset: Usually childhood or adolescence (though adults can develop it too).
- Mechanism: The body’s immune system mistakenly attacks insulin-producing cells.
- Inheritance: Can be hereditary but not always predictable.
- Mnemonic: “SON” → Self-destruction (autoimmune), Onset early, No insulin.
Type 2 Diabetes (T2DM)
- Cause: Insulin resistance combined with progressive insulin deficiency.
- Onset: Typically adulthood but increasingly common in children due to poor diet and sedentary lifestyle.
- Risk Factors: Obesity, high sugar diet, physical inactivity, genetics.
- Mnemonic: “YOU” → Your diet (sugary foods), Obesity, Unhealthy lifestyle.
Risk Factors for Diabetes Mellitus
Type 1 Diabetes
- Mostly genetic predisposition.
- Autoimmune conditions (e.g., thyroid disease, celiac disease).
- Viral infections that may trigger autoimmunity.
Type 2 Diabetes
Metabolic Syndrome: A cluster of risk factors including obesity, high blood pressure, and high cholesterol.
Mnemonic: “B-BOL”
- B – Blood Pressure > 130 systolic.
- B – Blood sugar meds or fasting glucose > 100 mg/dL.
- O – Obesity (waist size > 35” women, > 45” men).
- L – Lipids (high LDL, triglycerides, low HDL).
Having 3 or more of these risk factors indicates metabolic syndrome and a higher risk for Type 2 diabetes.
Diagnostic Labs for Diabetes
Accurate diagnosis is critical to managing diabetes. Common tests include:
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| Random Glucose | 70–115 mg/dL | – | ≥200 mg/dL |
| Fasting Glucose | <100 mg/dL | 100–125 mg/dL | ≥126 mg/dL |
| Oral Glucose Tolerance Test (OGTT) | <140 mg/dL | 140–199 mg/dL | ≥200 mg/dL |
| HbA1c (%) | <5.7% | 5.7–6.4% | ≥6.5% |
- HbA1c reflects average blood sugar over 2–3 months, making it a reliable long-term marker.
- Diagnosis requires confirmation with repeat testing unless symptoms are obvious.
Signs and Symptoms of Diabetes Mellitus
High Blood Sugar (Hyperglycemia)
Classic 3 Ps:
- Polyuria – Frequent urination.
- Polydipsia – Excessive thirst.
- Polyphagia – Increased hunger.
Other symptoms: fatigue, blurred vision, slow wound healing, frequent infections.
Mnemonic: “Hot and dry = sugar high.”
Low Blood Sugar (Hypoglycemia)
Occurs when blood glucose drops below 70 mg/dL.Symptoms:
- Cool, pale, sweaty skin.
- Shakiness, anxiety, irritability.
- Headache, dizziness, confusion.
Severe hypoglycemia can cause seizures, coma, or death.
Mnemonic: “Cold and clammy = need some candy.”Causes of Blood Sugar Imbalances
Causes of High Blood Sugar (Hyperglycemia)
- Skipping insulin or oral diabetic medications.
- Stress (hospital stay, illness, infection).
- Corticosteroids (prednisone).
- Poor dietary control.
Causes of Low Blood Sugar (Hypoglycemia)
- Skipping meals.
- Excessive exercise without adequate food intake.
- Alcohol consumption.
- Insulin overdose or peak insulin times.
Treatment and Patient Education
Diet Management
- Avoid: Simple sugars (soda, candy, white bread, juice).
- Encourage: Complex carbs and high-fiber foods (brown rice, whole wheat, beans).
- Tip: Brown is good, white is bad (referring to bread, rice, flour).
Diabetic Foot Care
Feet are especially vulnerable due to poor circulation and neuropathy.
- Daily inspection for wounds.
- Properly fitting shoes (no sandals, no high heels).
- Cotton socks, not nylon.
- Cut toenails straight, not curved.
- Avoid hot baths and harsh foot treatments.
- Report non-healing wounds immediately.
Complications of Diabetes Mellitus
If uncontrolled, diabetes can damage multiple organs:
| Organ | Complication |
|---|---|
| Kidney | Diabetic nephropathy (↑ Creatinine > 1.3) |
| Eye | Retinopathy → blindness |
| Heart | Hypertension, atherosclerosis, coronary artery disease |
| Brain | Stroke (cerebrovascular accident) |
| Nerves | Peripheral neuropathy (loss of sensation, foot ulcers) |
Long-term control of blood sugar is essential to prevent these devastating outcomes.
Management of Hypoglycemia
If Patient is Awake
- Give fast-acting carbs: juice, soda, crackers, low-fat milk.
- Avoid high-fat foods like peanut butter or whole milk as they slow sugar absorption.
If Patient is Unconscious
- Immediate IV dextrose (D50).
- Emergency glucagon injection if IV access unavailable.
Mnemonic: “Hypogly brain will die – treat fast!”
Table: Quick Reference for Diabetes Mellitus
| Feature | Type 1 Diabetes | Type 2 Diabetes |
|---|---|---|
| Onset | Childhood/Adolescence | Adulthood (increasing in children) |
| Cause | Autoimmune, no insulin production | Insulin resistance + ↓ production |
| Body Type | Lean | Overweight/Obese |
| Treatment | Insulin only | Diet, exercise, oral meds, insulin |
| Risk Factors | Genetic, autoimmune | Obesity, sedentary lifestyle, metabolic syndrome |
| Prevention | Not preventable | Largely preventable with lifestyle changes |
FAQs on Diabetes Mellitus
1. Can Type 1 diabetes be prevented?
No. Type 1 diabetes is an autoimmune condition and cannot be prevented. However, research is ongoing into vaccines and immune therapies.
2. Is Type 2 diabetes reversible?
Yes, in many cases, early Type 2 diabetes can be reversed with weight loss, healthy diet, and regular exercise. Some patients may achieve long-term remission.
3. What is the difference between Type 1 and Type 2 diabetes?
Type 1 results from lack of insulin production, while Type 2 arises from insulin resistance and eventual insulin deficiency.
4. How often should diabetics check their blood sugar?
It depends on treatment. Type 1 diabetics usually check multiple times daily, while stable Type 2 diabetics may check less frequently depending on their doctor’s advice.
5. What is diabetic ketoacidosis (DKA)?
A life-threatening complication of Type 1 diabetes caused by extremely high blood sugar and ketone buildup. It requires emergency treatment.
6. Can diabetics live a normal life?
Absolutely. With proper treatment, diet, exercise, and monitoring, people with diabetes can lead long, healthy lives.
