Y

Yeast bezoar A peristent foreign body, bezoar, in the stomach consisting of yeast. A yeast bezoar is a rare complication of gastric surgery. See Bezoar.

Yellow fever A viral disease occuring in central Africa and central and south America, spread by mosquitoes. Fever and headache after a 48 hours incubation period are mild symptoms, but the disease can be severe, including nausea, vominting and constipation. Only symptomatic supportive therapy is available.

Yersin, Aleksandre J.E. (1863-1943) A Swiss bacteriologist working in Paris, who has given his name to the Yersinia-bacterias.

Yersinia A group of gram-negative anaerobic rod-shaped bacterias belonging to the Enterobacteriaceae-family. To this bacteria genus belongs Yersinia pestis, the bacteria causing plague, and Yersinia enterocolitica and Yersinia pseudotuberculosis, bacterias causing acute bowel infections in humans.

Yin and Yang An ancient Chinese belief that all things have aspects opposing them. Health is believed to be a state where Yin and Yang are in an optimal balance. Yin is thought to be associated with the solid organs in our body, heart, liver, kidneys, and yang is associated with the hollow organs, for example the gastrointestinal canal.

Yr (Abbr) Year(s)

Yoga An ancient Indian philosophy and way of life, where complete harmony between our body and mind is achieved by special exercise, breathing and meditation.

Yo-yo dieting The phenomen, when a patient is treating his obesity with diet, and sometimes loose weight, then the diet fails, and he regain weight, and then ha again looses weigth, and so on.The weight cycling due to this diet may have adverse medical and psychological consequenses.