A yeast infection is a common fungal infection caused by an overgrowth of yeast, most often Candida albicans. Yeast normally lives on the skin and inside the body in small amounts without causing harm. When the balance of microorganisms is disrupted, yeast can multiply and lead to infection. Yeast infections most commonly affect the vagina, mouth, skin folds, and diaper …

A yeast infection under the breast is a common skin condition caused by an overgrowth of yeast, most often Candida species. This type of infection is also known as intertrigo with secondary yeast involvement. It develops in warm, moist areas where skin folds rub together, creating an ideal environment for yeast to grow. The area beneath the breasts can easily …

Yellow fever is a serious viral infection transmitted to humans through the bite of infected mosquitoes, primarily Aedes and Haemagogus species. The disease is most commonly found in parts of Africa and South America. Yellow fever is named after the jaundice, or yellowing of the skin and eyes, that can occur in severe cases due to liver damage. The illness …

A yellow jacket sting occurs when a yellow jacket, a type of aggressive wasp, injects venom into the skin through its stinger. Yellow jackets are commonly found in many regions and often live in nests near the ground, in walls, or in outdoor structures. Unlike bees, yellow jackets can sting multiple times, making encounters particularly painful and sometimes dangerous. For …

Yellow nail syndrome is a rare condition that affects the nails, lungs, and lymphatic system. It is named for the yellow discoloration that develops in the fingernails and toenails. In addition to nail changes, the condition is often associated with breathing problems and swelling caused by fluid buildup, known as lymphedema. Yellow nail syndrome can occur at any age but …

Yellow tongue is a condition in which the surface of the tongue appears yellow instead of its usual pink color. It is usually harmless and temporary, but it can sometimes signal an underlying issue related to oral hygiene, lifestyle habits, infections, or digestive problems. The yellow color often develops when dead skin cells build up on the tongue and trap …

Yersiniosis is an infection caused by bacteria of the genus Yersinia, most commonly Yersinia enterocolitica. The infection usually affects the digestive system and is a cause of gastroenteritis. Yersiniosis is more common in infants and children, but it can occur at any age. People usually get yersiniosis by eating contaminated food, especially undercooked pork, or by drinking unpasteurized milk. Infection …

Zellweger syndrome is a rare, inherited genetic disorder that affects many parts of the body, especially the brain, liver and kidneys. It belongs to a group of conditions called Zellweger spectrum disorders, which result from problems with structures inside cells known as peroxisomes. Peroxisomes play a key role in breaking down fatty acids and toxins and in supporting normal brain …

Zika virus disease is an infection caused by the Zika virus, which is primarily spread through the bite of an infected Aedes species mosquito. These mosquitoes are most active during the daytime. Zika virus was first identified in Africa but has since spread to many parts of the world, including tropical and subtropical regions. Most people infected with Zika virus …

Zoonotic diseases are infections that spread between animals and humans. These diseases can be caused by bacteria, viruses, parasites or fungi. Transmission may occur through direct contact with animals, contact with animal waste, consumption of contaminated food or water, or through vectors such as mosquitoes, ticks and fleas. Zoonotic diseases are common worldwide and range from mild illnesses to serious, …