Catarrhal Jaundice resulting from obstruction to the duct by an inflammation of its mucous membrane is the commonest form. Any obstruction from within or without, will, however, cause it. Microscopically it is seen that the biliary capillaries are distended and the liver cells contain more or less pigment. The bile escapes from its normal channels, is taken up by the lymphatics, from which it passes into the circulation and thence to the tissues throughout the body. The secretions and exudations of the body may be distinctly tinged. The tissue first stained is the intima of the blood-vessels; finally the skin and the sclera, where it is seen most characteristically. According to the duration, the color will vary from a light yellow to a dark bronze-green; the longer continued, the darker the color. If little or no bile escapes, the feces will usually be very light in color, clay-like.

The retention of bile within the body is generally accompanied by quite marked disturbances, particularly of the nervous system. As the flow of bile is re-established the discoloration gradually disappears.