A1C — See: Glycosylated hemoglobin test (HbA1C)

Acidosis — too much acid in the body. For a person with diabetes, ketoacidosis is a type of acidosis.

Adult-onset diabetes — former term for type 2 diabetes, also formerly called noninsulin-dependent diabetes.

Albuminuria — more than normal amounts of a protein called albumin in the urine. Albuminuria may be a sign of kidney disease.

Alpha cell — a type of cell in an area of the pancreas called the Islets of Langerhans. Alpha cells make and release a hormone called glucagon, which increases the amount of glucose in the blood.

Amino acids — the building blocks of proteins; the main material of the body’s cells. Insulin is made of 51 amino acids joined together.

Antibodies — proteins that the body produces to protect itself from foreign substances (such as bacteria or viruses).

Artery — a large blood vessel that carries blood from the heart to other parts of the body. Arteries are thicker than veins and have stronger, more elastic walls.

Atherosclerosis — a disease of the arteries in the heart (also called coronary artery disease or arteriosclerosis). Atherosclerosis occurs when the normal lining of the arteries deteriorates, the walls of the arteries thicken and deposits of fat and plaque block the flow of blood through the arteries. The arteries that supply blood to the heart become severely narrowed, decreasing the supply of oxygen-rich blood to the heart — especially during times of increased activity.

Autoimmune disease — a disorder of the body’s immune system in which the immune system mistakes your body's own cells as invaders and attack them. Type 1 diabetes is an autoimmune disease.

Autonomic neuropathy — nerve damage most often affecting the digestive system, blood vessels, urinary system and sex organs. Autonomic nerves are not under a person's control and function on their own.

Background retinopathy — also called nonproliferative retinopathy. Is the early stage of retinopathy caused by diabetes. It does not usually impair vision.

Basal rate — continuous supply of low levels of insulin, such as provided by the insulin pump.

Beta cell — a type of cell in an area of the pancreas called the Islets of Langerhans. Beta cells make and release insulin, which controls the glucose level in the blood.

Blood glucose — See: Glucose.

++Blood pressure++ — the measurement of the pressure or force inside the blood vessels (arteries) with each beat of the heart. Blood pressure is written as two numbers; the first number, the systolic pressure, is the pressure in the arteries when the heart beats and fills the arteries with blood. The second number, the diastolic pressure, is the pressure in the arteries when the heart rests between beats.

Blood urea nitrogen (BUN) — waste product of the kidneys. Increased BUN levels may indicate early kidney damage.

Bunion — a bump or bulge on the first joint of the big toe caused by the swelling of a sac of fluid under the skin. Shoes that fit well can prevent bunions from forming. Bunions may lead to other problems, such as serious infection.

Callus — a small area of skin, usually on the foot, that has become thick and hard from rubbing or pressure. Calluses may lead to other problems, such as serious infection. Shoes that fit well can prevent calluses from forming.

Calorie — energy that comes from food. Carbohydrates, protein, fat and alcohol all have calories. Fats have the most calories per gram.

Carbohydrate — one of the three main classes of nutrients and a source of energy. Carbohydrates are mainly sugars and starches that the body breaks down into glucose.

Cardiologist — a doctor who takes care of people with heart disease; a heart specialist.

Cardiovascular — relating to the heart and blood vessels (arteries, veins and capillaries).

Certified diabetes educator (CDE) — a health care professional who has met special requirements and is certified by the National Certification Board for Diabetes Educators to teach people with diabetes how to manage their condition.

Cholesterol — a waxy, odorless substance made by the liver that is an essential part of cell walls and nerves. Cholesterol plays an important role in body functions such as digestion and hormone production. In addition to being produced by the body, cholesterol comes from animal foods that we eat. Too much cholesterol may cause a build-up in the artery walls and lead to atherosclerosis.

Coma — a severe emergency in which a person is not conscious. Severe high or low blood sugar can cause a coma.

Continuous glucose monitor (CGM) — a sensor inserted under the skin that updates and reports glucose levels approximately every 5 minutes to the user. Home blood sugar monitoring may be required in order to calibrate the CGM and confirm readings.

Dawn phenomenon — a sudden rise in blood glucose levels in the early morning hours. This is more common in people with type 1 diabetes than type 2 diabetes.

Dehydration — great loss of body water. If a person with diabetes has a very high blood sugar level, it causes increased water loss, and the person becomes very thirsty.

Delta cell — a type of cell in the pancreas which releases other pancreatic hormones.

Dextrose — See: Glucose.

Diabetes: see Type 1 diabetes and type 2 diabetes

Diabetic ketoacidosis (DKA) — severe, untreated hyperglycemia (high blood sugar) that needs emergency treatment. DKA happens when there is not enough insulin. Ketoacidosis can lead to coma and even death.

Dietitian — an expert in nutrition who helps people plan the type and amount of foods to eat for special health needs. A registered dietitian (RD) has special qualifications.

Emergency medical identification — cards, bracelets, or necklaces with a written message, used by people with diabetes or other medical conditions to alert others in case of a medical emergency.

Endocrinologist — a doctor who treats people who have problems with their endocrine glands. The pancreas is an endocrine gland.

Fasting plasma glucose test — a lab test that measures a person’s blood glucose level after fasting or not eating anything for 10 to 12 hours. Normal fasting blood glucose is less than 100 mg/dl for people who do not have diabetes. A diagnosis of diabetes is made when two blood tests show that your fasting blood glucose level is greater than or equal to 126 mg/dl.

Fats —substances that help the body use some vitamins and keep the skin healthy. They are also the major way the body stores energy. In food, there are two types of fats; saturated and unsaturated.

Fructose — a type of sugar found in many fruits and vegetables and in honey. Fructose is used to sweeten some diet foods.

Gangrene — the death of body tissues, usually due to a lack of blood supply, especially in the legs and feet.

Gastroparesis — a form of nerve damage that affects the stomach. Food is not digested properly and does not move through the stomach normally.

Gestational diabetes mellitus— a high blood glucose level that is discovered during pregnancy. As pregnancy progresses, there is an increased need for glucose for the developing baby. Additionally, hormone changes during pregnancy affect the action of insulin, resulting in high blood glucose levels. Usually, blood glucose levels return to normal after childbirth. However, women who have had gestational diabetes are at increased risk of developing type 2 diabetes later in life.

Glaucoma — an eye disease associated with increased pressure within the eye. Glaucoma can damage the optic nerve and cause impaired vision and blindness.

Glucagon — a hormone that raises the level of glucose (sugar) in the blood. Glucagon is sometimes injected when a person has lost consciousness (passed out) from a low blood sugar reaction. The injected glucagon helps raise the level of glucose in the blood.

Glucose — a simple sugar found in the blood. It is the body’s main source of energy; also known as dextrose.

Glucose tolerance test — a test that can be used to determine if a person has diabetes. The test is done in a lab or doctor’s office in the morning before the person has eaten. First a sample of blood is taken. Then the person drinks a liquid that has glucose (sugar) in it. Periodically, another sample of blood is taken to see how the body processes the glucose in the blood.

Glycosylated hemoglobin test (HbA1c) — the average amount of glucose that has been in a person’s blood over the past two to three months. It can be used to diagnose diabetes. It is also used along with home glucose monitoring to determine overall diabetes management. A level of 6.5% or higher is a diagnosis of diabetes. The target HbA1c for most people with diabetes is less than 7%.

High blood pressure — a condition when the blood flows through the blood vessels at a force greater than normal. High blood pressure strains the heart, harms the arteries, and increases the risk of heart attack, stroke and kidney problems. Also called hypertension.

High blood sugar — See: Hyperglycemia

Home blood glucose monitoring — a way in which a person can measure how much glucose (sugar) is in the blood. Also called self monitoring of blood glucose.

Hormone — a chemical released by the endocrine glands and other tissues to help control certain functions in the body. For instance, insulin is a hormone made by the beta cells in the pancreas, and when released, it triggers other cells to use glucose for energy.

Human insulin — bio-engineered insulin that is very similar to insulin made by your own body.

Hyperglycemia — high blood sugar. Many things can cause hyperglycemia. It occurs when the body does not have enough insulin or cannot use the insulin it does have.

Hypertension — See: High blood pressure

Hypoglycemia — low blood glucose. Hypoglycemia in people with diabetes is often caused by an imbalance in diabetes medications, food intake, and/or activity levels.

Impotence — persistent inability of the penis to become erect or stay erect. Men with diabetes may become impotent if blood sugar levels are high for a long time due to nerve and blood vessel damage caused by the high blood sugar.

Injection site rotation — changing the areas on the body where a person injects insulin. If the same injection site is used over and over again, hardened areas, lumps or indentations can develop under the skin which keep the insulin from being used properly. These lumps or indentations are called lipodystrophies.

Injection sites — recommended places on the body where people can inject insulin. These sites include the back of the upper arm, the abdomen, the thighs and the buttocks.

Insulin — a hormone that helps the body use glucose for energy. The beta cells of the pancreas make insulin.

Insulin dependent diabetes — former term used for type 1 diabetes, also formerly called juvenile diabetes.

Insulin pump — a small, computerized device that is worn on a belt , in a pocket, or under clothes. Most insulin pumps delivers insulin through a small, flexible tube inserted under the skin. It delivers a steady flow of insulin 24 hours a day, and on-demand doses programmed by the user for food or high blood sugar.

Insulin reaction — See: Hypoglycemia

Insulin receptors — areas on the outer part of a cell that allow insulin in the blood to join or bind with the cell. When the cell and insulin bind together, the cell can take glucose from the blood and use it for energy.

Insulin resistance — when a person’s body will not allow insulin to work properly in the body. This condition can occur when a person is overweight, and it often improves when the person loses weight.

Insulin shock — loss of consciousness as a result of severe hypoglycemia (low blood sugar).

Juvenile diabetes — former term used for type 1 diabetes.

Ketoacidosis — See: Diabetic ketoacidosis (DKA)

Ketones — the waste products of fat burning. When your blood glucose gets too high, the body breaks down its own fat and protein for energy instead of glucose. When fat is used, ketones appear in your urine and blood. A large amount of ketones can lead to a serious condition called diabetic ketoacidosis.

Kidney Disease — See: Nephropathy

Lancet — a fine, sharp pointed needle for pricking the skin. Used in blood glucose monitoring.

Laser treatment — the use of a strong beam of light (laser) to heal a damaged area. A person with retinopathy from diabetes might receive laser treatments to heal blood vessels in the eye.

Late-onset diabetes — former term used for type 2 diabetes.

Lipid — See: Cholesterol

Low blood sugar — See: Hypoglycemia

Metabolic syndrome – a collection of health risks that increase the chance of developing heart disease, stroke and diabetes. It is also known as Syndrome X, insulin resistance syndrome and dysmetabolic syndrome.

Metabolism — all of the physical and chemical processes in the body which occur when food is broken down, energy is created, and wastes are produced.

Mg/dl (milligrams per deciliter) — measurement that indicates the amount of glucose in a specific amount of blood.

Nephropathy — disease of the kidneys caused by damage to the small blood vessels in the kidneys . People with diabetes may develop nephropathy as a result of high blood sugar damaging the blood vessels.

Neuropathy — nerve damage. People with diabetes may develop neuropathy as a result of high blood sugar damaging the blood vessels and nerves.

Non-insulin dependent diabetes — former term for type 2 diabetes.

Nutritionist — See: Dietitian

Obesity —too much body fat for a person’s age, height, and gender. Obesity is a risk factor for type 2 diabetes and insulin resistance.

Ophthalmologist — a doctor who treats people with eye diseases.

Optometrist — a person professionally trained to test the eyes and to detect and treat eye problems and some diseases by prescribing and adapting corrective lenses.

Oral medications — medications taken by mouth.

Pancreas — an organ behind the lower part of the stomach that is about the size of a hand. It has many roles, including the production of insulin and glucagon.

Peak action — the time when the effect of something is as strong as it can be, such as when insulin is having the most effect on blood glucose.

Periodontal disease — damage to the gums and tissues around the teeth. People who have high blood sugar are more likely to have periodontal disease than people who do not .

Peripheral neuropathy — a type of nerve damage most commonly affecting the feet and legs. The arms, abdomen and back may rarely be affected.

Peripheral vascular disease (PVD) — any abnormal condition that affects the blood vessels outside the heart and lymphatic vessels. Often occurs as decreased blood flow to the hands and feet. People with diabetes may develop PVD as a result of high blood sugar damaging the blood vessels.

Podiatrist — a health professional who diagnoses and treats foot problems.

Polydipsia — excessive thirst that lasts for long periods of time; may be a sign of diabetes.

Polyphagia —excessive hunger and eating; may be a sign of diabetes. People with polyphagia as a result of diabetes often lose weight even though they are eating more than normal.

Polyunsaturated fat — a type of fat that comes from vegetables.

Polyuria — increased need to urinate often; a common sign of diabetes.

Pre-mixed insulin – a mixture of insulin that contains two different types of insulin. Using pre-mixed insulin prevents someone from having to take two injections at the same time or mixing insulin from two vials (bottles).

Protein — one of three main classes of nutrients. Proteins are made of amino acids, which are called the "building blocks of the cells." The cells need proteins to grow and to mend themselves. Protein is found in many foods such as meat, fish, poultry, eggs, legumes and dairy products.

Renal — relating to the kidneys.

Renal threshold — the point at which the blood is holding so much of a substance, such as glucose, that the kidneys allow the excess to "spill" into the urine.

Retina — the center part of the back lining of the eye that senses light. It has many small blood vessels that can be harmed by high blood sugar levels.

Retinopathy — a disease of the small blood vessels in the retina of the eye. People with diabetes may develop retinopathy as a result of high blood sugar damaging the blood vessels in the eyes.

Risk factor — anything that increases the chance of a person developing a disease or condition.

Saccharin — an artificial sweetener that is sometimes used in place of sugar because it has no calories.

Somogyi effect — also called rebound effect. A swing to a high level of glucose in the blood after an extremely low level It often happens as the result of an untreated low blood sugar during the night. People who experience high levels of blood glucose in the morning may need to test their blood glucose levels in the middle of the night. If blood glucose levels are repeatedly low overnight, adjustments in evening snacks or insulin doses may be recommended.

Sucrose —table sugar; a form of sugar that the body must break down into a more simple form before the blood can absorb it and take it to the cells.

Sugar — a type of carbohydrate. Sugar is a quick and easy fuel for the body to use. Some types of sugar are lactose, glucose, fructose and sucrose.

Triglyceride — fats carried in the blood from the food we eat. Most of the fats we eat, including butter, margarines and oils, are in triglyceride form. Excess calories, alcohol or sugar in the body are converted into triglycerides and stored in fat cells throughout the body. The body needs insulin to remove this type of fat from the blood.

Type 1 diabetes — a type of diabetes in which the insulin-producing cells (beta cells) of the pancreas are damaged. People with type 1 diabetes produce little or no insulin, so glucose cannot get into the body’s cells for use as energy. This causes blood glucose to rise. People with type 1 diabetes must use insulin injections to manage their blood glucose.

Type 2 diabetes — a type of diabetes in which the insulin produced is either not enough or doesn’t work properly in the body. As a result, glucose cannot get into the body’s cells for use as energy. This causes blood glucose to rise.

Ulcer — a break in the skin; a deep sore. People with high blood sugar levels may develop ulcers from minor scrapes on the feet or legs, from cuts that heal slowly, or from the rubbing of shoes that don’t fit well. Ulcers can become infected and should be treated promptly.

Unit of insulin — the basic measure of insulin. U-100 is the most common concentration of insulin. U-100 means that there are 100 units of insulin per milliliter (ml) of liquid.

Urinary tract infection (UTI) – an infection of the urinary system (kidneys, bladder, and/or the tubes that connect them. Symptoms can include burning or pain with urination and frequent urination. People with high blood sugar levels have a higher risk of getting a UTI than people with target blood sugar levels.

Vaginitis - an inflammation or infection of the vaginal tissues, usually caused by a fungus. A woman with this condition may have itching or burning or vaginal discharge. Women who have high blood sugar levels may develop vaginitis more often than women who have target blood sugar levels.

Vascular — relating to the body's blood vessels (arteries, veins and capillaries).

Vein — a blood vessel that carries blood to the heart.

Vitrectomy — a procedure in which the gel from the center of the eyeball is removed because it has blood and scar tissue in it that blocks vision. An eye surgeon replaces the clouded gel with a clear fluid.

Yeast infection – a fungal infection of male or female genitals. Symptoms can include itching, soreness, white discharge, and pain with intercourse. People with high blood sugars have a higher risk of getting a yeast infection than people with target blood sugar levels.

Last reviewed by a Cleveland Clinic medical professional on 08/30/2019.

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