Our hair has a complex physiology, and in fact, a variety of healthy phyiologic functions including helping us thermoregulate, be sensory, socially interact, and physically protect us!
Many hormones control the growth of our hair including growth hormone, insulin, insulin-like growth factors, the steroid family glucocorticoids, estrogen, and testosterone. Locally at the hair follicle, there are genetic differences in how the hair follicle can respond to the enzymes that convert testosterone to even more potent androgen dihydrotestosterone, also called DHT. The regulation of these hormones will cause our hair to grow. Or not grow.
Genetically we have all of our numbers of hair follicles preset around the middle of fetal life. At age 40, we start loosing the hairs on our head, literally. They cease to be there, we start to drop from a max of about 100 thou to 150 thou, to, well, lets just say "fewer."
About 70% of women by age 80 report significant hair loss. And yet not all hairs stop growing. Under the influence of the male hormones the fine hairs on the body start to coarsen, and women may notice a big change in some cases. . So hairs that might have been downy, soft, basically so un-noticeable you never noticed, they now become thicker and darker and seem to have "appeared" out of no-where. Many of these changes are due to changes in the levels of hormones to each other. Rather than specifically age related it is more years from menopause related. Hormones have a role, and it's more linked to male hormones, but exactly which and what levels, that remains to be worked out.
All these levels can be measured with salivary testing, blood testing, and in some cases urinary hormone testing. If you are noticing changes, and want to know more about how your hair grows, come in for an appointment! 217-356-3736.