A diabetic is a person whose body cannot properly regulate blood sugar. This happens either because the pancreas stops producing insulin (the hormone that moves sugar from your blood into your cells) or because the body’s cells stop responding to insulin effectively. About 15.8% of U.S. adults have diabetes, and roughly 4 in 10 of those don’t yet know it.
The condition comes in several forms, affects the body in different ways over time, and requires daily attention to food, activity, and often medication. Here’s what that actually looks like.
How Blood Sugar Regulation Normally Works
When you eat, your body breaks food down into glucose, a sugar that enters your bloodstream. Your pancreas detects this rise in blood sugar and releases insulin. Insulin acts like a key: it binds to receptors on the surface of your cells and signals them to open up and absorb glucose for energy. Once glucose moves out of the blood and into cells, your blood sugar drops back to a normal range.
In a person with diabetes, this system breaks down at one of two points. Either the pancreas can’t make enough insulin, or the cells ignore insulin’s signal. Both result in glucose building up in the blood instead of entering cells, a state called hyperglycemia.
Type 1 vs. Type 2 vs. Gestational Diabetes
Type 1 diabetes is an autoimmune condition. The immune system attacks and destroys the insulin-producing cells in the pancreas, leaving the body with little to no insulin at all. It typically appears in childhood or adolescence and requires daily insulin from the time of diagnosis.
Type 2 diabetes is far more common and develops gradually. The body still produces insulin, but cells become increasingly resistant to it, often driven by excess weight and aging. The pancreas tries to compensate by making more insulin, but over time it can’t keep up. Type 2 tends to appear in middle-aged and older adults, though it’s increasingly diagnosed in younger people as obesity rates rise.
Gestational diabetes develops during pregnancy and usually resolves after delivery. However, it signals an increased risk of developing type 2 diabetes later in life.
Common Symptoms of High Blood Sugar
The hallmark signs of uncontrolled diabetes are frequent urination, excessive thirst, and unexplained weight loss. These are directly connected: when blood sugar is too high, the kidneys try to flush the excess glucose out through urine, pulling water along with it. That fluid loss triggers intense thirst. Meanwhile, because cells aren’t getting the glucose they need for fuel, the body starts breaking down fat and muscle, causing weight loss even when appetite increases.
As blood sugar climbs higher, neurological symptoms can develop, including lethargy, confusion, difficulty seeing clearly, and in severe cases, loss of consciousness. People with type 1 diabetes may also experience nausea, vomiting, abdominal pain, and a fruity odor on their breath, which signals a dangerous condition called diabetic ketoacidosis where the blood becomes too acidic.
How Diabetes Is Diagnosed
Diabetes is diagnosed primarily through blood tests that measure how much sugar is in your blood. The most common is the A1C test, which reflects your average blood sugar over the past two to three months. An A1C between 5.7% and 6.4% indicates prediabetes, a stage where blood sugar is elevated but not yet high enough for a diabetes diagnosis. An A1C of 6.5% or higher on two separate tests confirms diabetes.
Fasting blood sugar tests are also used. You fast overnight, then have blood drawn in the morning. A result of 100 to 125 mg/dL falls in the prediabetes range, while 126 mg/dL or above points to diabetes.
What High Blood Sugar Does to the Body Over Time
The real danger of diabetes isn’t a single high reading. It’s years of chronically elevated blood sugar quietly damaging blood vessels and nerves throughout the body. Excess glucose in the blood triggers a chain of harmful processes: it binds to proteins and forms compounds called advanced glycation end products, which stiffen and damage blood vessel walls. It generates an overload of unstable molecules that injure cells, particularly the delicate lining of blood vessels. It also triggers chronic low-grade inflammation that accelerates the buildup of fatty plaques in arteries.
In small blood vessels, these changes thicken the vessel walls, reduce blood flow, and starve tissues of oxygen. This is why diabetes can damage the eyes (potentially causing blindness), the kidneys (potentially leading to kidney failure), and the nerves in the feet and hands (causing numbness, tingling, and slow wound healing). In large blood vessels, the same processes accelerate atherosclerosis, raising the risk of heart attack and stroke. These complications develop over years, which is why catching and managing diabetes early matters so much.
The Risk of Low Blood Sugar
People being treated for diabetes also face the opposite problem: blood sugar dropping too low, below 70 mg/dL. This typically happens when medication, insulin, or physical activity lowers blood sugar faster than food intake raises it. Early symptoms include a fast heartbeat, shaking, sweating, anxiety, dizziness, and sudden hunger. If blood sugar drops below 54 mg/dL, the situation becomes serious, potentially causing seizures, loss of consciousness, or an inability to walk or see clearly.
Some people who have had diabetes for more than five to ten years develop what’s called hypoglycemia unawareness, where the body stops producing noticeable warning symptoms during a low. This makes it harder to catch and treat drops early, which is one reason regular blood sugar monitoring is so important.
Daily Life With Diabetes
Managing diabetes is largely a daily, self-directed effort built around food, movement, and monitoring. On the nutrition side, many people use one of two meal planning approaches: carbohydrate counting (tracking grams of carbs at each meal to predict blood sugar impact) or the plate method (filling half a 9-inch plate with non-starchy vegetables, one quarter with lean protein, and one quarter with whole grains or fruit). Portion awareness matters too. A serving of meat is roughly the size of a deck of cards, and a serving of cooked rice or pasta is about the size of a fist.
Sugar-sweetened drinks, including fruit juice, are one of the fastest ways to spike blood sugar and are generally best avoided. Sodium intake should stay under 2,300 mg per day, and alcohol, if consumed at all, should be limited to one drink a day for women and two for men.
Physical activity plays an equally important role. The standard recommendation is at least 150 minutes per week of moderate aerobic exercise (brisk walking, cycling, swimming) spread across at least three days, plus two to three sessions of strength training. Even breaking up long periods of sitting every 30 minutes provides measurable blood sugar benefits. If you take insulin, checking your blood sugar before, during, and after exercise is important. A pre-exercise level below 90 mg/dL means you should eat a small snack with 15 to 30 grams of carbs before starting.
Losing more than 5% of body weight through calorie reduction and lifestyle changes significantly improves blood sugar control in people with type 2 diabetes and can even help reverse prediabetes. Working with a dietitian has been shown to lower A1C by 0.3% to 2% in type 2 diabetes, which is comparable to what some medications achieve.
How Diabetes Is Treated
Type 1 diabetes always requires insulin, delivered through injections or an insulin pump, because the body produces none on its own. Insulin must be stored properly (away from extreme heat, cold, and direct sunlight) and doses are adjusted based on what you eat, your activity level, and your current blood sugar readings.
Type 2 diabetes treatment often starts with lifestyle changes alone. When those aren’t enough, oral medications that help the body use insulin more effectively or reduce the amount of sugar the liver releases are typically the next step. Some people with type 2 diabetes eventually need insulin as well, especially as the condition progresses over years.
Regardless of type, managing diabetes means checking blood sugar regularly, keeping snacks or glucose tablets on hand for lows, planning ahead for sick days (illness can cause unpredictable blood sugar swings), and coordinating with your healthcare team before starting any new medication, even over-the-counter ones. Many people with diabetes also wear medical identification bracelets or carry cards so that others can help in an emergency.