glycemia
Meaning of glycemia: A measurement rather than a substance: the word names how much glucose is in the blood, which is why it takes prefixes.
Definition of glycemia
Glycemia is the concentration of glucose in the blood, the quantity present in a given volume rather than the sugar itself. It is one of the most tightly held values in the body, kept within a narrow band by insulin, glucagon and the liver. The word usually appears with a prefix, as hyperglycemia for a raised level and hypoglycemia for a low one.
How glycemia is built
- gluc/o, glyc/o Combining form · Greek sugar, glucose
- -emia Suffix · Greek condition of the blood
A medical term is read from its ending backwards: the suffix first, then the prefix, then the root. See all 223 word parts.
What holds the level steady?
Two hormones pull in opposite directions and the liver does most of the physical work. After a meal, insulin from the pancreas moves glucose out of the blood into muscle, fat and liver, where it is burned or stored. Between meals, glucagon signals the liver to release stored glucose back into the circulation and, later, to manufacture fresh glucose from other materials. Adrenaline, cortisol and growth hormone push the level up as well, which is why illness, injury and stress raise it even in people whose control is otherwise normal.
Why does the brain make this a priority?
Nerve cells burn glucose almost exclusively and hold no reserve of their own. A supply interrupted for minutes produces confusion, sweating, tremor and eventually loss of consciousness, so the body defends the lower end of the range far more aggressively than the upper end. Harm from a high level accumulates over years, while harm from a low level can arrive within an hour, and that difference in tempo shapes how the two are regarded.
What do the prefixes mean?
| Term | Meaning | Common setting |
|---|---|---|
| Normoglycemia | Level within the usual range | Health |
| Hyperglycemia | Level above the usual range | Diabetes, infection, steroid treatment |
| Hypoglycemia | Level below the usual range | Insulin and some diabetes tablets, prolonged fasting, liver failure |
The plain word carries no verdict on whether the value is normal.
How is it measured?
A sample of blood is tested for its glucose content, either in a laboratory or with a small meter using a drop from a fingertip. Continuous sensors worn under the skin report a related value from the fluid between cells, which lags a little behind the true blood sugar during rapid change. A separate test measures the fraction of hemoglobin that glucose has attached itself to, giving an average over the preceding weeks rather than a single moment.
Also known as
Used in a sentence
Glycemia was monitored closely while the steroid dose was tapered.
Good to know
Glycemia names the concentration rather than the sugar, so the word implies nothing about whether a value is normal until a prefix such as hyper or hypo is attached.
Word origin
Where “glycemia” comes from
Formed from the Greek glykys, meaning sweet, and haima, meaning blood.