Chronic yeast syndrome is an as-yet unproven disorder in which the excessive growth of yeast throughout the body is said to cause a variety of symptoms. Chronic yeast syndrome has been claimed to cause acne, allergies, skin rashes, fatigue, arthritis, depression, headaches, premenstrual syndrome, and loss of sexual drive.

Medical studies have not been able to prove the existence of this syndrome. Some doctors will treat people for chronic yeast syndrome with oral antifungal medications, which kill yeast. In addition, those affected may be advised to follow a diet low in sugar and yeast products.