Perfect Balance
A hot flush is an attempt by your body to cool down. It is a universal strategy that is used by your body to lower your core temperature. The hot flush occurs when your brain directs blood flow to the skin. The heat in the blood is radiated out into the environment more readily when more blood circulates near the skin. Our experience of this is a flushing of the skin and the feeling of heat.
Another strategy that your body uses is perspiration. Your brain stimulates the release of perspiration onto the surface of the skin, where it evaporates giving the feeling of a chill. It’s a form of air conditioning really. As the water (perspiration) evaporates, heat is lost and you feel cooler.
We are all familiar with this experience when we perspire on a hot day. Another experience that most of us have had utilizes both of these body mechanisms to cool us down
Regulation of body temperature during illness
The hypothalamus controls many core body systems. The stress response also centers in this part of the brain. The hypothalamus lies just above the pituitary gland-the body’s master gland. The hypothalamus stimulates the pituitary gland to release different hormones which are released into the bloodstream and travel throughout the body.. During stress the hypothalamus stimulates the pituitary to release a hormone called ACTH which in turn stimulates the adrenal glands.
The hypothalamus also controls our reproductive cycle
The hypothalamus stimulates the pituitary gland to secrete two hormones, follicle stimulating hormone (FSH) and leutinizing hormone (LH). FSH and LH in turn stimulate the ovaries to release estrogen and progesterone at different points in the menstrual cycle. A complex feedback cycle between the ovaries, hypothalamus and pituitary, using these four hormones as messengers, regulates the reproductive cycle. The timing of ovulation and menstruation depends on the rhythmic communication of these organs, via the four hormones.
So we see that the hypothalamus controls a number of critical processes in our bodies such as body temperature, the stress response and the reproductive cycle. And this is not all, but it is all we need to discuss for the purpose of explaining the cause of hot flushes.
Sex hormone levels drop as menopause approaches
Towards the end of our reproductive years, a woman’s ovaries begin to secrete less progesterone and estrogen. In response the hypothalamus secretes higher levels of FSH and LH to try to get the levels back up again. The resulting high levels of FSH in the hypothalamus and body are thought to throw off the body’s ability to monitor and regulate our body temperature.
Dropping reproductive hormones disrupt the hypothalamus
Your brain initiates an emergency strategy and routes the blood and the skin of the face and neck which become flushed and hot.
During this phase, heat is radiating out of your body, bringing the core temperature down. Then your brain stimulates the release of perspiration from the skin… you then begin to perspire, sometimes profusely. As you do so, and the perspiration evaporates, there is the sensation of a chill. This is the completion of the hot flush.
Researchers call it a narrowing of the thermoregulatory zone
Your brain normally keeps your body temperature within what it considers a safe zone. Your temperature can rise and fall within this safe zone and your brain remains unconcerned. During perimenopause, premenopause and menopause researchers speculate that there is a narrowing of the brain’s definition of the safe zone.
What would have previously been considered a “safe” rise in temperature is now misread by the hypothalamus as a dangerous elevation in body temperature. In an attempt to quickly bring body temperature back into the safe zone, it employs its universal strategy for quick cooling. Blood is routed to the skin (flushing) followed by the release of sweats
Remedying hot flashes and sweats by restoring estrogen levels
Email: susan@healthyhormones.com.au
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