| Term |
Synonyms |
Definition |
| Xanthelasma |
|
The fatty deposits around the eyes that are common in elderly people and are associated with high levels of cholesterol in the blood. |
| Xanthine |
|
A bronchodilator drug that is used to treat asthma. |
| Xanthomatosis |
|
A condition in which fatty deposits occur in various parts of the body, possibly leading to atherosclerosis. |
| X chromosome |
|
One of the two sex chromosomes; determines female sex characteristics. |
| Xeroderma pigmentosum |
|
A genetic disorder in which the skin is extremely sensitive to sunlight, causing it to age prematurely and leaving the individual particularly susceptible to skin cancer. |
| Xerophthalmia |
|
Excessive dryness of the cornea and conjunctiva due to a lack of vitamin A. |
| Xerostomia |
Dry mouth |
The condition can be caused by a number of things, including rheumatoid arthritis, diabetes, kidney failure, infection with HIV (the virus that causes AIDS), drugs used to treat depression, and radiation treatment for mouth or
throat cancer. |
| X-linked disorder |
|
A genetic disorder in which the abnormal gene is located on the X chromosome; those affected are almost always men. |
| X-ray |
Roentgen ray |
Electromagnetic vibrations of short wave length that penetrate most matter and produce an image on film. |
| Xylitol |
|
A sweetener found in plants and used as a substitute for sugar; it is called a nutritive sweetener because it provides calories, just like sugar. |
| XYY syndrome |
|
A disorder in which a man has an extra Y chromosome, causing him to be unusually tall and to have behavioral disorders. |
