diabetes mellitus

Overview
Diabetes mellitus is a chronic condition that affects how your body processes blood sugar (glucose). It occurs when the body either doesn’t produce enough insulin or can’t use insulin effectively, leading to elevated blood sugar levels. There are several types, but the most common are Type 1, Type 2, and gestational diabetes.

Why It’s Important
If not managed properly, diabetes can lead to serious complications like heart disease, kidney failure, nerve damage, vision loss, and even amputation. It requires lifelong management, but early detection and lifestyle changes can greatly reduce the risk of complications.

Quick Facts

  • Affects over 37 million people in the U.S., with many more undiagnosed

  • Can affect children (Type 1) and adults (mostly Type 2)

  • Type 1 diabetes is an autoimmune disease and usually starts in youth

  • Type 2 diabetes is largely related to lifestyle and genetics

  • Gestational diabetes occurs during pregnancy and usually resolves afterward

  • Type 2 is the most common, accounting for over 90% of cases

  • Diabetes is chronic but manageable

What Happens in the Body
When you eat, your body breaks down carbohydrates into glucose, which enters your bloodstream. Insulin, a hormone made by the pancreas, helps move glucose from the blood into cells for energy.
In diabetes:

  • Type 1: The immune system destroys insulin-producing cells in the pancreas

  • Type 2: The body becomes resistant to insulin or doesn’t make enough

  • Gestational: Hormonal changes during pregnancy cause insulin resistance

Common Signs and Symptoms

  • Increased thirst and urination

  • Unexplained weight loss (more common in Type 1)

  • Fatigue

  • Blurred vision

  • Slow wound healing

  • Tingling or numbness in hands or feet (Type 2)

  • Frequent infections (e.g., skin, urinary tract)

Diagnosis

  • Fasting blood glucose test (≥126 mg/dL = diabetes)

  • A1C test (≥6.5%) shows average blood sugar over 2–3 months

  • Oral glucose tolerance test (used in pregnancy and some cases)

  • Diagnosed if two tests are in the diabetic range or symptoms + random glucose ≥200 mg/dL

  • Anyone with symptoms or risk factors should be tested

Treatment and Management

  • Type 1:

    • Requires daily insulin injections or an insulin pump

    • Frequent blood sugar monitoring

  • Type 2:

    • Lifestyle changes: diet, exercise, weight loss

    • Oral medications (e.g., metformin)

    • Insulin may be needed over time

  • Gestational:

    • Usually managed with diet and monitoring, sometimes insulin

  • Newer treatments: GLP-1 receptor agonists, SGLT2 inhibitors

  • All types benefit from regular checkups, blood pressure control, and eye/foot care

  • Not curable, but highly manageable

Risks and Complications

  • Heart disease and stroke

  • Kidney damage (diabetic nephropathy)

  • Nerve damage (neuropathy)

  • Retinopathy and blindness

  • Foot ulcers and amputations

  • Increased risk of infections

  • Mental health issues like depression or diabetes distress

Who Is at Risk

  • Type 1: Genetic predisposition, family history, often starts in children

  • Type 2:

    • Over age 45

    • Overweight/obesity

    • Sedentary lifestyle

    • Family history

    • Higher prevalence in African American, Hispanic, Native American, and Asian populations

  • Gestational: Pregnant women, especially those overweight or with a family history

Related Conditions

  • Prediabetes (elevated blood sugar but not diabetic range)

  • Hypertension

  • High cholesterol

  • Polycystic ovary syndrome (PCOS)

  • Sleep apnea

When to See a Doctor

  • If you experience persistent symptoms like frequent urination, fatigue, or weight changes

  • If you have risk factors or family history

  • If you’re pregnant and your doctor recommends screening

  • If you’re diagnosed, follow up regularly to monitor A1C, kidney function, and complications

Last Updated: June 21, 2025