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.
* Oxytocin headache: The release of the hormone Oxytocin, can also trigger a headache. This hormone is released during the let down of milk and can also cause nausea during breastfeeding. This type of lactation headache will usually subside after a few minutes of breastfeeding.