-osis
Meaning of -osis: An abnormal state or an ongoing process, and the ending most often mistaken for a second word meaning inflammation.
Definition of -osis
The suffix -osis marks a condition or process, most often an abnormal one, in whatever the root names. Fibrosis is the laying down of scar tissue, stenosis is narrowing, cyanosis is a blue discoloration of the skin. It carries no sense of inflammation and no sense of infection, and a handful of terms built on it describe entirely normal processes.
What does the ending actually claim?
That a state exists or a process is under way. Nothing more is implied about cause, speed or seriousness. That vagueness is deliberate, since the ending was needed for changes that could be seen and named long before anyone understood them. The plural is formed by changing the ending to oses, so one stenosis and several stenoses. Some of these words describe ordinary biology rather than disease: mitosis is routine cell division, osmosis is water movement across a membrane, and phagocytosis is an immune cell swallowing a particle.
Is it a synonym for inflammation?
No, and treating it as one produces real errors. Inflammation has its own ending, and the two describe different things happening in the same tissue. Hepatitis means the liver is inflamed, while hepatosis describes liver disease without that inflammatory picture. Dermatitis means inflamed skin, while dermatosis covers any skin disease at all, inflamed or not. A closely related ending, iasis, also means a condition, and it is used mostly for the presence of something that should not be there, as in nephrolithiasis, meaning stones in the kidney.
How does it work across the body?
| Term | Root | What it describes |
|---|---|---|
| fibrosis | fibr, fiber | scar tissue replacing working tissue |
| necrosis | necr, death | tissue that has died |
| stenosis | sten, narrow | a passage or valve that has narrowed |
| sclerosis | scler, hard | tissue that has hardened or scarred |
| thrombosis | thromb, clot | a clot forming inside a blood vessel |
| mitosis | mit, thread | ordinary cell division, a normal process |
The pattern holds across every system, so fibrosis in the lung and in the liver are the same process in different places, and necrosis means dead tissue wherever it is found.
Terms built on -osis
73 entries in this glossary use this word part. Each one follows the same pattern.
- -sclerosis An ending that reports texture, not cause: the tissue named in front of it has become…
- -stenosis The ending that reports a passage has been squeezed tighter, whether by scar, swelling, a…
- acoustic neurofibromatosis A genetic condition in which tumors form on the nerves of the inner ear and cause loss of…
- actinic keratosis Often easier to feel than to see, these sandpaper patches mark skin that has absorbed…
- adenosis An overgrowth of glandular tissue that is harmless in itself but can imitate cancer…
- amyloidosis What matters is which protein misfolded, because the answer sets the organs at risk, the…
- anastomosis An anastomosis is a connection joining two tubular structures, such as blood vessels or…
- antituberculosis Describes a drug or effect that works against tuberculosis (a contagious bacterial…
- asbestosis Scarring, not cancer: this is the fibrotic lung disease of asbestos exposure, and it is…
- aspergillosis Aspergillosis is a fungal infection caused by Aspergillus mold that most often affects…
- atherosclerosis The sudden events, heart attack and most strokes, come less from slow narrowing than from…
- bisphosphonate-associated osteonecrosis The necrosis (death) of bone tissue caused by treatment with a bisphosphonate (a drug or…
- calcinosis A condition in which abnormal amounts of calcium salts are found in soft tissue, such as…
- candidosis A condition in which Candida albicans, a type of yeast, grows out of control in moist…
- carcinomatosis Carcinomatosis describes carcinoma that has spread extensively through the body or…
- carcinosis Carcinosis is an older term for widespread dissemination of carcinoma through the body,…
- chronic idiopathic myelofibrosis A progressive, chronic disease in which the bone marrow is replaced by fibrous tissue and…
- cirrhosis A type of chronic, progressive liver disease in which liver cells are replaced by scar…
- coloanal anastomosis A surgical procedure in which the colon is attached to the anus after the rectum has been…
- cyanosis The color depends on how much hemoglobin is traveling without oxygen rather than on the…
- cystic fibrosis A common hereditary disease in which exocrine (secretory) glands produce abnormally thick…
- deep vein thrombosis A clot lodged in a leg vein matters less for the leg than for what happens if a piece of…
- diagnosis Seldom a single moment, a diagnosis is usually narrowed from a list of candidates and can…
- diffuse hyperplastic perilobar nephroblastomatosis A childhood condition in which abnormal tissue grows on the outer part of one or both…
- diverticulosis Diverticulosis is the presence of multiple diverticula in the colon wall, usually causing…
- ecchymosis The flat purple patch left when blood escapes under the skin, larger than a pinpoint spot…
- endometriosis A benign condition in which tissue that looks like endometrial tissue grows in abnormal…
- essential thrombocytosis Essential thrombocytosis describes a persistently elevated platelet count arising from a…
- familial adenomatous polyposis It runs through families on a single dominant gene, yet a sizeable share of cases begin…
- familial polyposis Familial polyposis is an inherited disorder causing hundreds of colorectal polyps that…
- fat necrosis Fat necrosis is a benign condition in which damaged fat tissue can form a firm lump that…
- fibromatosis Growths that invade locally and return after removal yet never travel to distant organs,…
- fibrosis Fibrosis is the buildup of dense scar-like tissue in an organ, which can stiffen it and…
- genetic infantile agranulocytosis An inherited disorder in which there is a lower-than-normal number of neutrophils (a type…
- hemochromatosis A condition in which the body takes up and stores more iron than it needs.
- hemophagocytic lymphohistiocytosis Hemophagocytic lymphohistiocytosis is a rare, life-threatening syndrome of overwhelming…
- hydronephrosis Swelling of the drainage spaces is a clue rather than a diagnosis, and it can linger…
- hyperkeratosis Hyperkeratosis is a thickening of the skin's outer keratin layer that can result from…
- hypnosis Responsiveness to suggestion is a fairly stable individual trait, and a minority of…
- idiopathic myelofibrosis A progressive, chronic disease in which the bone marrow is replaced by fibrous tissue and…
- idiopathic pulmonary fibrosis A disease in which the alveoli (tiny air sacs at the end of the bronchioles in the lungs)…
- infantile genetic agranulocytosis An inherited disorder in which there is a lower-than-normal number of neutrophils (a type…
- Langerhans cell histiocytosis Long filed as an odd inflammatory reaction, it is now recognized as a clonal growth…
- lymphomatoid granulomatosis Destructive growth of lymph cells, usually involving the lungs, skin, kidneys, and…
- meiosis The division that halves the chromosome count and shuffles the deck, so no two eggs or…
- meningeal carcinomatosis One condition carrying at least five names, recognized by trouble that refuses to point…
- metabolic acidosis Metabolic acidosis is a drop in blood pH caused by excess acid production or loss of the…
- mitosis Cells rely on mitosis for both growth and the routine replacement of worn out tissue,…
- molecular diagnosis The process of identifying a disease by studying molecules, such as proteins, DNA, and…
- monoclonal B-cell lymphocytosis A laboratory finding rather than an illness: identical B cells circulating in numbers too…
- multiple endocrine adenomatosis A rare, inherited disorder that affects the endocrine glands and can cause tumors in the…
- multiple sclerosis Scattered patches of damage explain the scattered symptoms, since what a person notices…
- myelofibrosis Scar tissue crowds out the marrow, so blood cell production migrates to the spleen and…
- myelomatosis A type of cancer that begins in plasma cells (white blood cells that produce antibodies).
- necrosis Cells dying by accident spill their contents and inflame the area around them, unlike the…
- osteoporosis Spinal fractures are the most common kind and often pass unnoticed, surfacing later as…
- phagocytosis The process by which a phagocyte (a type of white blood cell) surrounds and destroys…
- polyposis Polyposis is the development of numerous polyps, growths projecting from a mucous…
- precancerous dermatosis A skin disease marked by scaly or thickened patches on the skin and often caused by…
- primary myelofibrosis A progressive, chronic disease in which the bone marrow is replaced by fibrous tissue and…
- prognosis A statement about probability across many similar cases, which is why it can shift as new…
- psychosis Loss of insight is what makes psychosis distinctive, since the experiences feel entirely…
- ptosis Ptosis is a drooping of the upper eyelid that can be present from birth or develop later…
- radiation fibrosis The formation of scar tissue as a result of radiation therapy.
- radiation necrosis The death of healthy tissue caused by radiation therapy.
- renal tubular acidosis A rare disorder in which structures in the kidney that filter the blood are impaired,…
- sarcoidosis Some cases settle on their own without treatment while others scar the lungs permanently,…
- sclerosing adenosis A benign condition in which scar-like tissue is found in a gland, such as the breast…
- scoliosis The twist counts as much as the bend, since rotation pushes the ribs into the hump that…
- senile keratosis A thick, scaly patch of skin that may become cancer.
- side-to-end coloanal anastomosis A surgical procedure in which the side of the colon is attached to the anus after the…
- solar keratosis A sun-damage lesion easier to feel than to see, and the visible tip of a much wider field…
- thrombosis Thrombosis is the formation of a blood clot within a blood vessel or the heart, which can…
Also known as
Used in a sentence
The suffix -osis in the term indicated an abnormal process rather than an inflammatory one.
Good to know
The ending means an abnormal condition or process rather than inflammation, so dermatosis covers any skin disease while dermatitis states specifically that the skin is inflamed.
Word origin
Where “-osis” comes from
A Greek noun ending built on verbs in -oun, denoting a state, a condition or the process of becoming; the plural form is -oses.