Thrush is a medical condition caused by an overgrowth of the Candida fungus in the mouth and throat. Small amounts of Candida are normally present but are kept in balance by the immune system and bacteria. However, illnesses, medications, stress, or other factors can disrupt this balance and cause Candida to grow excessively, resulting in thrush. Symptoms include white patches in the mouth and throat, soreness, and strange tastes. Thrush is diagnosed visually or microscopically and treated with antifungal medications, by addressing its underlying cause, or using home remedies to reduce discomfort.