medicine Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pract ...

, a bleb is a

blister A blister is a small pocket of body fluid (lymph, serum, plasma, blood, or pus) within the upper layers of the skin, usually caused by forceful rubbing (friction), burning, freezing, chemical exposure or infection. Most blisters are filled wi ...

-like protrusion (often hemispherical) filled with

serous fluid In physiology, serous fluid or serosal fluid (originating from the Medieval Latin word ''serosus'', from Latin ''serum'') is any of various body fluids resembling Serum (blood), serum, that are typically pale yellow or transparent and of a benign ...

. Blebs can form in a number of tissues by different pathologies, including

frostbite Frostbite is a skin injury that occurs when exposed to extreme low temperatures, causing the freezing of the skin or other tissues, commonly affecting the fingers, toes, nose, ears, cheeks and chin areas. Most often, frostbite occurs in the han ...

and can "appear and disappear within a short time interval". In pathology pulmonary blebs are small subpleural thin-walled air-containing spaces, not larger than 1-2 cm in diameter. Their walls are less than 1 mm thick. If they rupture, they allow air to escape into pleural space, resulting in a spontaneous

pneumothorax A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and shortness of breath. In a minority of cases, a one-way valve ...

. In

ophthalmology Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medic ...

, blebs may be formed intentionally in the treatment of

glaucoma Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye rem ...

. In such treatments, functional blebs facilitate the circulation of

aqueous humor The aqueous humour is a transparent water-like fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary body, a structure supporting the lens of the eyeball. It fills both the anterior and the posterior ...

, the blockage of which will lead to increase in eye pressure. Use of collagen matrix wound modulation device such as ologen during glaucoma surgery is known to produce vascular and functional blebs, which are positively correlated with treatment success rate. In the lungs, a bleb is a collection of air within the layers of the

visceral pleura The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls. The inner pleura, called the visceral pleura, covers the surface of each lung and dips bet ...

. In

breasts The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues. In females, it serves as the mammary gland, which produces and secret ...

a bleb is a milk blister (also known as blocked nipple pore, nipple blister, or “milk under the skin”).White spot on the nipple
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External links

*Medical definition of bleb o
MedicineNet.com

References

Skin conditions resulting from physical factors Medical terminology Ophthalmology {{disease-stub