-sclerosis
Meaning of -sclerosis: An ending that reports texture, not cause: the tissue named in front of it has become abnormally firm or scarred.
Definition of -sclerosis
-sclerosis is a suffix meaning abnormal hardening of a tissue or structure. It attaches to a word part naming what has hardened, so arteriosclerosis describes stiffened artery walls and nephrosclerosis describes hardened blood vessels within the kidney. The firmness usually comes from normal soft tissue being replaced by dense fibrous scar, and sometimes from mineral deposited where the tissue should stay flexible.
What does the ending mean?
Hardening. A structure described with this ending has lost its normal give and become firm, stiff or leathery. Usually the cause is fibrosis, in which working tissue is replaced by dense collagen scar. Sometimes it is calcium laid down in a wall meant to stay flexible. The ending is descriptive rather than diagnostic: it reports how tissue now looks and feels under the microscope, and says nothing at all about why.
What does it attach to?
A word part naming the tissue, organ or structure that has hardened, joined to the ending by the linking letter o. Arteri/o produces arteriosclerosis and nephr/o produces nephrosclerosis, while the ending itself never changes. Reading one of these words is a matter of translating the front half and adding the word hardening to it.
| Word | Word part in front | What it names | What the term describes |
|---|---|---|---|
| arteriosclerosis | arteri/o | artery | Stiff, thickened artery walls |
| atherosclerosis | ather/o | gruel or porridge | Fatty plaque built up inside an artery wall |
| nephrosclerosis | nephr/o | kidney | Hardened small vessels inside the kidney |
| otosclerosis | ot/o | ear | Extra bone locking a middle ear bone in place |
| scleroderma | scler/o, moved to the front | hard | Thickened, tight skin, with the parts reversed |
Why is multiple sclerosis named that way?
Not because arteries have hardened. In multiple sclerosis the immune system strips the insulating sheath from nerve fibers in the brain and spinal cord, and the damaged areas heal as firm scarred patches called plaques. Multiple describes how many there are and how widely scattered they lie; sclerosis describes their texture. The disease was named for what those patches felt like in the laboratory long before anyone understood the cause. Symptoms that fade between attacks, a partial remission, are typical of the commonest pattern. Amyotrophic lateral sclerosis is built the same way, naming hardening along the side columns of the spinal cord.
Which endings are confused with it?
-stenosis is the main one. It means narrowing of a passage, which is a separate property: a vessel can stiffen without narrowing and can narrow without stiffening. Atherosclerosis does both at once, which is where the confusion starts. The bare ending -osis means only an abnormal condition and carries no information about texture. Scler/o also works at the front of a word, where the sclera is the tough white coat of the eye.
Terms built on -sclerosis
2 entries in this glossary use this word part. Each one follows the same pattern.
- atherosclerosis The sudden events, heart attack and most strokes, come less from slow narrowing than from…
- multiple sclerosis Scattered patches of damage explain the scattered symptoms, since what a person notices…
Also known as
Used in a sentence
The biopsy showed sclerosis of the small vessels within the sampled tissue.
Good to know
The ending records texture rather than cause, so multiple sclerosis, atherosclerosis and scleroderma share a word part while sharing no mechanism, and hardened tissue is a finding that several unrelated processes produce.
Word origin
Where “-sclerosis” comes from
From the Greek sklerosis, a hardening, built on skleros, meaning hard. The same root gives the sclera, the tough white outer coat of the eye.