Infective causes of vaginal itching tend to be accompanied by other symptoms such as abnormal vaginal discharge.
Yeast infections may give rise to thick, cottage-cheese like discharge associated with soreness.
Other symptoms like spotting (bleeding in between periods) may also suggest an underlying infection.
A careful analysis of lifestyle triggers may be useful in shedding light on what non-infectious factors may be contributing to your itch.
Vaginal Itching that occurs only during your period may be related to skin irritation from menstrual pads, which itching after intercourse could be related to dermatitis from condoms, latex allergies, or irritation from chemicals found in spermicides or lubricants.
The visual appearance of any associated rash may sometimes also be helpful in helping your doctor discern the cause of vaginal itch.