Endotheliitis is an

immune response An immune response is a reaction which occurs within an organism for the purpose of defending against foreign invaders. These invaders include a wide variety of different microorganisms including viruses, bacteria, parasites, and fungi which could ...

within the

endothelium The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel ...

in blood vessels, in which they become

inflamed Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecu ...

. The condition can cause

oedema Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's tissue. Most commonly, the legs or arms are affected. Symptoms may include skin which feels tight, the area ma ...

of the surrounding tissue, including the stroma, and can cause irritation and pain. If it is within the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power ...

, it can result in permanent loss of vision. The condition can be caused by a number of factors, such as

mumps MUMPS ("Massachusetts General Hospital Utility Multi-Programming System"), or M, is an imperative, high-level programming language with an integrated transaction processing key–value database. It was originally developed at Massachusetts Gener ...

and

cytomegalovirus ''Cytomegalovirus'' (''CMV'') (from ''cyto-'' 'cell' via Greek - 'container' + 'big, megalo-' + -''virus'' via Latin 'poison') is a genus of viruses in the order ''Herpesvirales'', in the family ''Herpesviridae'', in the subfamily ''Betaherpe ...

under certain circumstances.

References

Vascular diseases Inflammations {{med-sign-stub