Symptoms of insect bites and stings. An insect bite or sting often causes a small lump to develop, which is usually very itchy. A small hole, or the sting itself, may also be visible. The lump may have an inflamed (red and swollen) area around it that may be filled with fluid. This is called a weal.
Hormones and the Brain. That's not to say estrogen isn't a major player in regulating moods. Estrogen acts everywhere in the body, including the parts of the brain that control emotion. Some of estrogen's effects include: 1  Increasing serotonin, and the number of serotonin receptors in the brain.
Many doctors believe that a long duration of significantly increased levels of estrogen, followed by a sudden drop in hormones, such as the time just before menopause, will cause more severe headaches than even menstrual headaches. While the reason hormonal fluctuations cause headaches during menopause is still inconclusive, most researchers agree it has to do with the effects that hormones, such as estrogen and progesterone, have on the brain and its blood vessels.