There are tests out there for candida but finding a doctor that believes in this condition is the problem. I think the common tests are stool and saliva tests. But most of doctors are in denial that it is a real problem. The most effective way to diagnose candida is by health history and symptoms. If you have a history of antibiotic use, birth control pill use, or steroid use, you likely have it. Also, if your diet consists of a lot of sweets, breads, pasta, or carbohydrates in general, you are a good candidate. Candida makes you crave these. The symptoms list is a mile long and can mask a lot of problems which 'conventional medicine' has labeled with their own names. Things like Irritable Bowel Syndrome, Crohn's Disease, or most GI problems are probably candida related. Also, skin problems like psoriasis, eczema, rosacea, acne, skin tags, and warts are candida related. If you feel lethargic, "fogged in", have trouble concentrating (ADD), lack of energy, have experienced weight gain, have chronic sinus or ear infections, chronic colds and flu, headaches, arthritis, nail fungus, chronic jock itch or athlete's feet, and allergies are all due to candida. Add to this a long list of diseases such as Diabetes, M.S. , Parkinson's, Alzheimer's, just to name a few, and you have a multi-billion dollar parasite. So, as you can see, doctors don't want to admit candida is the cause to all of these problems because it would severely cut into their profits.