When exterior Dampness invades the body, it tends to invade the lower part first, typically the legs. From the legs, it can flow upwards in the leg channels to settle in any of the pelvic cavity organs. If it settles in the female genital system it causes vaginal discharges, if it settles in the Intestines it will cause loose stools and if it settles in the Bladder it will cause difficulty, frequency and burning of urination. However, Dampness is also common in the head and always the cause of sinusitis for example.
Markus Schweiss (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons