Most women have vaginal discharge - a fluid produced by the vagina. It performs a cleaning, moisturizing, and protective function in your body by removing old cells from the uterus. It may vary in volume, but if accompanied by itching, smell or abnormal coloring (grey, green, brown, bright yellow), vaginal discharge serves as a signal of infection or disease. 

Vaginal itching can happen along with vaginal secretion or on its own. Some of the most common causes are:

1. STDs (trichomoniasis, gonorrhea, or chlamydia)
2. Yeast infection
3. Bacterial vaginosis (gray mucus and fishy smell) 
4. Low estrogen levels during menopause 
5. Foreign body in the vagina
6. Reaction to chemicals in creams.  

Lichen planus, desquamative vaginitis, or cancer of the reproductive female organs are less common reasons for vaginal discharge and itching.

Sources:

medlineplus.gov