What problems can be caused by candida overgrowth in the body?

Hundreds of problems. Candida overgrowth leads to increased intestinal permeability (leaky gut syndrome) which can cause food allergies ; autoimmune problems ; result in fatigue, "brain fog, "muscle ; joint pains, hormonal imbalances, frequent infections (sinus, lungs etc), abd. Pain, gas, constipation, skin rashes etc. See http://www.Yeastconnection.Com/pdf/yeastfullsurv.Pdf ; http://huff.To/15mbzao consult a holistic doc.
Many. The commonest candida infections involve the skin and genital area . In immunocompromised patients the mouth esophagus and into intestine can also be involved. That is usually a serious condition that needs aggressive treatment with antifungal antibiotics.