Hot flash | |
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Other names | Hot flushes |
Specialty | Gynecology |
Hot flashes (also known as hot flushes) are a form of flushing, often caused by the changing hormone levels that are characteristic of menopause. They are typically experienced as a feeling of intense heat with sweating and rapid heartbeat, and may typically last from two to 30 minutes for each occurrence.
Hot flashes, a common symptom of menopause and perimenopause, are typically experienced as a feeling of intense heat with sweating and rapid heartbeat, and may typically last from two to thirty minutes for each occurrence, ending just as rapidly as they began. The sensation of heat usually begins in the face or chest, although it may appear elsewhere such as the back of the neck, and it can spread throughout the whole body. [1] Some people feel as if they are going to faint. In addition to being an internal sensation, the surface of the skin, especially on the face, becomes hot to the touch. This is the origin of the alternative term "hot flush", since the sensation of heat is often accompanied by visible reddening of the face.
The hot-flash event may be repeated a few times each week or every few minutes throughout the day. Hot flashes may begin to appear several years before menopause starts and last for years afterwards. Some people undergoing menopause never have hot flashes. Others have mild or infrequent flashes. Those most affected experience dozens of hot flashes each day. In addition, hot flashes are often more frequent and more intense during hot weather or in an overheated room, the surrounding heat apparently making the hot flashes themselves both more likely to occur, and more severe.
Severe hot flashes can make it difficult to get a full night's sleep (often characterized as insomnia), which in turn can affect mood, impair concentration, and cause other physical problems. When hot flashes occur at night, they are called "night sweats". As estrogen is typically lowest at night, some people get night sweats without having any hot flashes during the daytime. [2]
If hot flashes occur at other times in a young female's menstrual cycle, then it might be a symptom of a problem with the pituitary gland; seeing a doctor is highly recommended. In younger females who are surgically menopausal, hot flashes are generally more intense than in older females, and they may last until natural age at menopause. [3]
Hot flashes in males could have various causes. It can be a sign of low testosterone. [4] [5] [6] Males with prostate cancer or testicular cancer can also have hot flashes, especially those who are undergoing hormone therapy with antiandrogens, also known as androgen antagonists, which reduce testosterone to castrate levels. [7] Males who are castrated can also get hot flashes. [8] [9] [10]
Some menopausal females may experience both standard hot flashes and a second type sometimes referred to as "slow hot flashes" or "ember flashes". The standard hot flash comes on rapidly, sometimes reaching maximum intensity in as little as a minute. It lasts at full intensity for only a few minutes before gradually fading.
Slow "ember" flashes appear almost as quickly but are less intense and last for around half an hour. Females who experience them may undergo them year round, rather than primarily in the summer, and ember flashes may linger for years after the more intense hot flashes have passed.
Research on hot flashes is mostly focused on treatment options. The exact cause and pathogenesis, or causes, of vasomotor symptoms (VMS)—the clinical name for hot flashes—has not yet been fully studied. [11] [12]
Hot flashes are associated with declining levels of estrogen (estrogen withdrawal) and other hormonal changes. [13] It does not appear that low levels of estrogen are the sole cause of hot flashes, as women who experience hot flashes have around the same plasma estrogen levels as women who do not have them, and prepubertal girls do not have hot flashes despite low estrogen levels. [13]
There are indications that hot flashes may be due to a change in the hypothalamus's control of temperature regulation. [14]
Transgender men also commonly report experiences of hot flashes. [15] This is linked to hormonal changes possible from many aspects of masculinizing gender-affirming care, including the use of gonadotropin-releasing hormone agonists as puberty blockers, [16] reduction of estrogen levels after having undergone oopherectomy, [17] and long term testosterone use reducing production of estradiols. [18]
Hormone replacement therapy may relieve many of the symptoms of menopause. However, oral HRT may increase the risk of breast cancer, stroke, and dementia and has other potentially serious short-term and long-term risks. [19] [20] Since the incidence of cardiovascular disease in women has shown a rise that matches the increase in the number of post menopausal women, recent studies have examined the benefits and side effects of oral versus transdermal application of different estrogens and found that transdermal applications of estradiol may give the vascular benefits lowering the incidences of cardiovascular events with fewer adverse side effects than oral preparations. [21] [22]
Women who experience troublesome hot flashes are advised by some to try alternatives to hormonal therapies as the first line of treatment. If a woman chooses hormones, they suggest she take the lowest dose that alleviates her symptoms for as short a time as possible. [23] The US Endocrine Society concluded that women taking hormone replacement therapy for 5 years or more experienced overall benefits in their symptoms including relief of hot flashes and symptoms of urogenital atrophy and prevention of fractures and diabetes. [24]
When estrogen as estradiol is used transdermally as a patch, gel, or pessary with micronized progesterone this may avoid the serious side effects associated with oral estradiol HRT since this avoids first pass metabolism (Phase I drug metabolism). [25] Women taking bioidentical estrogen, orally or transdermally, who have a uterus must still take a progestin or micronized progesterone to lower the risk of endometrial cancer. A French study of 80,391 postmenopausal women followed for several years concluded that estrogen in combination with micronized progesterone is not associated with an increased risk of breast cancer. [26] The natural, plant-derived progesterone creams sold over the counter contain too little progesterone to be effective. Wild yam (Dioscorea villosa) extract creams are not effective since the natural progesterone present in the extract is not bioavailable. [27]
SSRIs are a class of pharmaceuticals that are most commonly used in the treatment of depression. They have been found efficient in alleviating hot flashes. [28] On 28 June 2013 FDA approved Brisdelle (low-dose paroxetine mesylate) for the treatment of moderate-to-severe vasomotor symptoms (e.g. hot flashes and night sweats) associated with menopause. Paroxetine became the first and only non-hormonal therapy for menopausal hot flashes approved by FDA. [29]
Clonidine is a blood pressure-lowering medication that can be used to relieve menopausal hot flashes when hormone replacement therapy is not needed or not desired. For hot flashes, clonidine works by helping reduce the response of the blood vessels to stimuli that cause them to narrow and widen. [30] While not all women respond to clonidine as a hot flash medication, it can reduce hot flashes by 40% in some peri-menopausal women. [31]
Isoflavones are commonly found in legumes such as soy and red clover. The two soy isoflavones implicated in relieving menopausal symptoms are genistein and daidzein, and are also known as phytoestrogens. The half life of these molecules is about eight hours, which might explain why some studies have not consistently shown effectiveness of soy products for menopausal symptoms.[ citation needed ] Although red clover (Trifolium pratense) contains isoflavones similar to soy, the effectiveness of this herb for menopausal symptoms at relatively low concentrations points to a different mechanism of action. [32]
It is believed [ by whom? ] that dietary changes that include a higher consumption of phytoestrogens from sources such as soy, red clover, ginseng, and yam may relieve hot flashes.
Acupuncture has been suggested to reduce incidence of hot flashes in women with breast cancer and men with prostate cancer, but the quality of evidence is low. [38] [39]
It has been speculated that hot flashes are less common among Asian women. [40] [41]
Menopausal women who have more hot flashes have a higher risk of hypertension and cardiovascular disease. [42]
Menopause, also known as the climacteric, is the time when menstrual periods permanently stop, marking the end of reproduction. It typically occurs between the ages of 45 and 55, although the exact timing can vary. Menopause is usually a natural change. It can occur earlier in those who smoke tobacco. Other causes include surgery that removes both ovaries or some types of chemotherapy. At the physiological level, menopause happens because of a decrease in the ovaries' production of the hormones estrogen and progesterone. While typically not needed, a diagnosis of menopause can be confirmed by measuring hormone levels in the blood or urine. Menopause is the opposite of menarche, the time when a girl's periods start.
A progestogen, also referred to as a progestagen, gestagen, or gestogen, is a type of medication which produces effects similar to those of the natural female sex hormone progesterone in the body. A progestin is a synthetic progestogen. Progestogens are used most commonly in hormonal birth control and menopausal hormone therapy. They can also be used in the treatment of gynecological conditions, to support fertility and pregnancy, to lower sex hormone levels for various purposes, and for other indications. Progestogens are used alone or in combination with estrogens. They are available in a wide variety of formulations and for use by many different routes of administration. Examples of progestogens include natural or bioidentical progesterone as well as progestins such as medroxyprogesterone acetate and norethisterone.
Estrone (E1), also spelled oestrone, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estriol. Estrone, as well as the other estrogens, are synthesized from cholesterol and secreted mainly from the gonads, though they can also be formed from adrenal androgens in adipose tissue. Relative to estradiol, both estrone and estriol have far weaker activity as estrogens. Estrone can be converted into estradiol, and serves mainly as a precursor or metabolic intermediate of estradiol. It is both a precursor and metabolite of estradiol.
Bioidentical hormone replacement therapy (BHRT), also known as bioidentical hormone therapy (BHT) or natural hormone therapy, is the use of hormones that are identical on a molecular level with endogenous hormones in hormone replacement therapy. It may also be combined with blood and saliva testing of hormone levels, and the use of pharmacy compounding to obtain hormones in an effort to reach a targeted level of hormones in the body. A number of claims by some proponents of BHT have not been confirmed through scientific testing. Specific hormones used in BHT include estrone, estradiol, progesterone, testosterone, dehydroepiandrosterone (DHEA), and estriol.
Estradiol acetate (EA), sold under the brand names Femtrace, Femring, and Menoring, is an estrogen medication which is used in hormone therapy for the treatment of menopausal symptoms in women. It is taken by mouth once daily or given as a vaginal ring once every three months.
Drospirenone is a progestin and antiandrogen medication which is used in birth control pills to prevent pregnancy and in menopausal hormone therapy, among other uses. It is available both alone under the brand name Slynd and in combination with an estrogen under the brand name Yasmin among others. The medication is an analog of the drug spironolactone. Drospirenone is taken by mouth.
Norethisterone acetate (NETA), also known as norethindrone acetate and sold under the brand name Primolut-Nor among others, is a progestin medication which is used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. The medication available in low-dose and high-dose formulations and is used alone or in combination with an estrogen. It is ingested orally.
An estrogen patch, or oestrogen patch, is a transdermal delivery system for estrogens such as estradiol and ethinylestradiol which can be used in menopausal hormone therapy, feminizing hormone therapy for transgender women, hormonal birth control, and other uses. Transdermal preparations of estrogen are metabolized differently than oral preparations. Transdermal estrogens avoid the first pass through the liver and thus potentially reduce the risk of blood clotting and stroke.
Hypoestrogenism, or estrogen deficiency, refers to a lower than normal level of estrogen. It is an umbrella term used to describe estrogen deficiency in various conditions. Estrogen deficiency is also associated with an increased risk of cardiovascular disease, and has been linked to diseases like urinary tract infections and osteoporosis.
Hormone replacement therapy (HRT), also known as menopausal hormone therapy or postmenopausal hormone therapy, is a form of hormone therapy used to treat symptoms associated with female menopause. Effects of menopause can include symptoms such as hot flashes, accelerated skin aging, vaginal dryness, decreased muscle mass, and complications such as osteoporosis, sexual dysfunction, and vaginal atrophy. They are mostly caused by low levels of female sex hormones that occur during menopause.
Menerba, also known as Menopause Formula 101 (MF-101), is a botanical drug candidate that acts as a selective estrogen receptor modulator (SERM) which is being studied for its potential to relieve hot flashes associated with menopause. Menerba, an estrogen receptor beta (ERβ) agonist (ERBA), is part of a new class of receptor subtype-selective estrogens, which is selective in transcriptional regulation to one of the two known estrogen receptor (ER) subtypes. Menerba consists of 22 herbs that have been used historically in traditional Chinese medicine.
Ospemifene is an oral medication indicated for the treatment of dyspareunia – pain during sexual intercourse – encountered by some women, more often in those who are post-menopausal. Ospemifene is a selective estrogen receptor modulator (SERM) acting similarly to an estrogen on the vaginal epithelium, building vaginal wall thickness which in turn reduces the pain associated with dyspareunia. Dyspareunia is most commonly caused by "vulvar and vaginal atrophy."
Conjugated estrogens (CEs), or conjugated equine estrogens (CEEs), sold under the brand name Premarin among others, is an estrogen medication which is used in menopausal hormone therapy and for various other indications. It is a mixture of the sodium salts of estrogen conjugates found in horses, such as estrone sulfate and equilin sulfate. CEEs are available in the form of both natural preparations manufactured from the urine of pregnant mares and fully synthetic replications of the natural preparations. They are formulated both alone and in combination with progestins such as medroxyprogesterone acetate. CEEs are usually taken by mouth, but can also be given by application to the skin or vagina as a cream or by injection into a blood vessel or muscle.
Estradiol (E2) is a medication and naturally occurring steroid hormone. It is an estrogen and is used mainly in menopausal hormone therapy and to treat low sex hormone levels in women. It is also used in hormonal birth control for women, in feminizing hormone therapy for transgender women, and in the treatment of hormone-sensitive cancers like prostate cancer in men and breast cancer in women, among other uses. Estradiol can be taken by mouth, held and dissolved under the tongue, as a gel or patch that is applied to the skin, in through the vagina, by injection into muscle or fat, or through the use of an implant that is placed into fat, among other routes.
Progesterone (P4), sold under the brand name Prometrium among others, is a medication and naturally occurring steroid hormone. It is a progestogen and is used in combination with estrogens mainly in hormone therapy for menopausal symptoms and low sex hormone levels in women. It is also used in women to support pregnancy and fertility and to treat gynecological disorders. Progesterone can be taken by mouth, vaginally, and by injection into muscle or fat, among other routes. A progesterone vaginal ring and progesterone intrauterine device used for birth control also exist in some areas of the world.
Fezolinetant, sold under the brand name Veozah among others, is a medication used for the treatment of hot flashes (vasomotor symptoms) due to menopause. It is a small-molecule, orally active, selective neurokinin-3 (NK3) receptor antagonist which is under development by for the treatment of sex hormone-related disorders. It is taken by mouth. It is developed by Astellas Pharma which acquired it from Ogeda (formerly Euroscreen) in April 2017.
An estrogen (E) is a type of medication which is used most commonly in hormonal birth control and menopausal hormone therapy, and as part of feminizing hormone therapy for transgender women. They can also be used in the treatment of hormone-sensitive cancers like breast cancer and prostate cancer and for various other indications. Estrogens are used alone or in combination with progestogens. They are available in a wide variety of formulations and for use by many different routes of administration. Examples of estrogens include bioidentical estradiol, natural conjugated estrogens, synthetic steroidal estrogens like ethinylestradiol, and synthetic nonsteroidal estrogens like diethylstilbestrol. Estrogens are one of three types of sex hormone agonists, the others being androgens/anabolic steroids like testosterone and progestogens like progesterone.
Estetrol (E4) is an estrogen medication and naturally occurring steroid hormone which is used in combination with a progestin in combined birth control pills and is under development for various other indications. These investigational uses include menopausal hormone therapy to treat symptoms such as vaginal atrophy, hot flashes, and bone loss and the treatment of breast cancer and prostate cancer. It is taken by mouth.
The pharmacology of estradiol, an estrogen medication and naturally occurring steroid hormone, concerns its pharmacodynamics, pharmacokinetics, and various routes of administration.