Systemic candidiasis occurs when Candida species, which are normally harmless inhabitants of the skin and mucous membranes, invade deeper tissues and enter the bloodstream. This can lead to infections in the liver, spleen, kidneys, heart, and other organs. The most common species responsible for this infection is Candida albicans, although other species such as Candida glabrata and Candida parapsilosis can also be implicated.