physiological (normal) vaginal discharge

Last reviewed 07/2021

Physiological discharge vaginal discharge

  • normal and healthy for women of reproductive age to have some degree of vaginal discharge
  • quantity and type of cervical mucus changes during the menstrual cycle as a result of hormonal fluctuations
  • prior to ovulation, estrogen levels increase, altering cervical mucus from non-fertile (thick and sticky) to fertile (clearer, wetter, stretchy and slippery). After ovulation, estrogen levels fall and progesterone levels increase; cervical mucus becomes thick, sticky and hostile to sperm.

The vagina is colonised with commensal bacteria (normal vaginal flora)

  • rising estrogen levels at puberty lead to colonisation with lactobacilli which metabolise glycogen in the vaginal epithelium to produce lactic acid. Thus the vaginal environment is acidic and normally has a pH <=4.5
  • other commensal bacteria include anaerobes, diphtheroids, coagulase-negative staphylococci and alpha-haemolytic streptococci.
  • some commensal organisms can cause a change in discharge if they 'overgrow'
    • includes Candida albicans, Staphylococcus aureus and Streptococcus agalactiae (Group B streptococcus).


  • 1) FSRH and BASHH Guidance (February 2012) Management of Vaginal Discharge in Non-Genitourinary Medicine Settings.