Candida is a form of yeast fungus which occurs naturally in the mouth and intestines, and an overgrowth can cause a number of adverse health effects. – Tiredness and exhaustion. Common symptoms of Candida include: Overgrowth can include: Tiredness and exhaustion, Constant Yeast Infections, Itchy Skin, Ears or Feet, Headaches, thrush or bladder infections, Bloating after eating and a slow digestive system.