What causes menopausal hot flushes?
A hot flush is an attempt by your body to cool down. It is a universal strategy that is used 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
Remember when you had a fever as a child. You felt hot to the touch as your mother placed the back of her hand against your forehead. Your body, in an attempt to fight against an infection, raised your temperature. Your body heated up and you could feel yourself burning up. The heat radiated from your skin. Eventually the brain decided that you were getting too hot and decided to cool you down. We refer to this as having the fever break. When you fever broke, you felt cold chills and sweated. Again these events were controlled by your brain. The part of your brain that regulates temperature is called the hypothalamus. But the hypothalamus does more than control body temperature.
One of the brain's major control centers lies in the hypothalamus
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 hormonal rhythm behind our monthly reproductive cycle also depends on the hypothalamus. The hypothalamus registers estrogen and progesterone in the blood and thus monitors how much of each the ovaries are secreting. 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
Remember that the hypothalamus regulates a number of critical body systems. We spoke of the stress response, the reproductive cycle and temperature regulation. All of these functions are housed in the same facility. Imagine a suite of rooms in the same office space. In one office someone is hysterical because ovarian production of estrogen and progesterone is dropping. She is on the phone shouting orders, trying to get levels back up. This commotion upsets everyone in the office suite, particularly the person next door who happens to be in charge of regulating body temperature.
Stressed by the commotion next door, this employee who is responsible for monitoring body temperature is on edge and jumpy. She is in a state of alarm. Slight changes in body temperature are misread as dangerous variations from normal. Thinking that our body temperature has risen dangerously high, our brain initiates and emergency strategy.
It routes blood the skin of the face and neck which become flushed and hot. In some women the response is body wide. Blood is routed to the skin of the legs, back, arms, chest, face and top of the head. It results in a wave of heat that surges through the body skin. Women frequently describe a surge of heat in the chest that radiates upward into the neck, face and scalp.
During this phase, heat is radiating out of the body, bringing the core temperature down. Then the brain stimulates the release of perspiration from the skin€"the sweats. One begins to perspire, sometimes profusely. As one does 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
Normally your brain keeps your body temperature within what it considers a safe zone. Your temperature can rise and fall within this safe zone and the 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 perspiration (sweats).
Remedying hot flashes and sweats by restoring estrogen levels
A strategy for naturally restoring estrogen levels has been shown to dramatically reduce hot flushes and sweats in perimenopausal women. This strategy employs phytoestrogens or plant made estrogen like molecules found in herbs and food.
Regulation of body temperature during illness
Remember when you had a fever as a child. You felt hot to the touch as your mother placed the back of her hand against your forehead. Your body, in an attempt to fight against an infection, raised your temperature. Your body heated up and you could feel yourself burning up. The heat radiated from your skin. Eventually the brain decided that you were getting too hot and decided to cool you down. We refer to this as having the fever break. When you fever broke, you felt cold chills and sweated. Again these events were controlled by your brain. The part of your brain that regulates temperature is called the hypothalamus. But the hypothalamus does more than control body temperature.
One of the brain's major control centers lies in the hypothalamus
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 hormonal rhythm behind our monthly reproductive cycle also depends on the hypothalamus. The hypothalamus registers estrogen and progesterone in the blood and thus monitors how much of each the ovaries are secreting. 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
Remember that the hypothalamus regulates a number of critical body systems. We spoke of the stress response, the reproductive cycle and temperature regulation. All of these functions are housed in the same facility. Imagine a suite of rooms in the same office space. In one office someone is hysterical because ovarian production of estrogen and progesterone is dropping. She is on the phone shouting orders, trying to get levels back up. This commotion upsets everyone in the office suite, particularly the person next door who happens to be in charge of regulating body temperature.
Stressed by the commotion next door, this employee who is responsible for monitoring body temperature is on edge and jumpy. She is in a state of alarm. Slight changes in body temperature are misread as dangerous variations from normal. Thinking that our body temperature has risen dangerously high, our brain initiates and emergency strategy.
It routes blood the skin of the face and neck which become flushed and hot. In some women the response is body wide. Blood is routed to the skin of the legs, back, arms, chest, face and top of the head. It results in a wave of heat that surges through the body skin. Women frequently describe a surge of heat in the chest that radiates upward into the neck, face and scalp.
During this phase, heat is radiating out of the body, bringing the core temperature down. Then the brain stimulates the release of perspiration from the skin€"the sweats. One begins to perspire, sometimes profusely. As one does 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
Normally your brain keeps your body temperature within what it considers a safe zone. Your temperature can rise and fall within this safe zone and the 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 perspiration (sweats).
Remedying hot flashes and sweats by restoring estrogen levels
A strategy for naturally restoring estrogen levels has been shown to dramatically reduce hot flushes and sweats in perimenopausal women. This strategy employs phytoestrogens or plant made estrogen like molecules found in herbs and food.
