Yeasts are of great importance economically and socially, and may have beneficial or detrimental effects. Many fungi, particularly yeasts, are involved in industrial fermentation processes like the production of bread and alcohol, while other fungi are essential to the cheese-making process.
At times, systemic infection can happen when fungi enter the body by inhalation, but subsequently spread to other organ systems via the blood, causing serious, even fatal disease. Fungi also cause disease in plants, and can have a devastating effect on crops of economic importance, either on the living plant or in storage subsequent to harvesting. Rusts, smuts and mildews are all examples of common plant diseases caused by fungi.
Among the yeast infections in human most common are skin rashes and vaginal infections in women. These infections usually cause extensive itching, rashes and discharge in women.