The normal balance of micro-organisms in the vagina can also be upset during pregnancy as a result of the increase in vaginal sugar levels that may be caused by increased estrogen levels. In some women, taking the contraceptive pill can have a similar effect and will also cause a yeast infection. Some women suffer from a yeast infection before their period (premenstrual yeast infection) as menstrual blood raises the pH level of the vagina, making it less acidic and thereby disturbing the balance between the micro-organisms.

The use of scented bubble bath, soap and vaginal deodorants can irritate the vagina and trigger a yeast infection in some women. Using tampons or wearing nylon tights and underwear can cause a yeast infection to occur and some women find that a diet high in sugar can also trigger one.

Men usually only develop a yeast infection when it is passed to them by a sexual partner. The symptoms of a yeast infection in men are fairly similar to those seen in women, although some men can carry the infection without showing any symptoms at all. They may have itching or burning at the tip of the penis or under the foreskin. A thick, white discharge may also develop under the foreskin and can make it difficult to retract. They may also experience discomfort when passing urine.

If a sexual partner is not treated for a yeast infection at the same time as the sufferer, they can pass the infection back to the sufferer again. Both partners must be treated even if the male has no symptoms.

What tests confirm a diagnosis of yeast infection?
If it is the first yeast infection, your doctor  may take a culture to confirm the diagnosis. If the a yeast infection recurs, the symptoms are usually recognized and no further testing should be necessary.