Menstruation, which occurs monthly, is the release of an unfertilized egg

Menopause is defined as 12 months without a period

Menopause is officially when a woman stops getting her period, meaning she has stopped ovulating and can no longer get pregnant. A woman has to go a full year without bleeding or spotting to know she has hit menopause.

How menopause affects mental health

Menopause, a natural biological process, occurs in three stages: perimenopause (hormone fluctuations), menopause (end of menstrual cycles), and postmenopause (12 months without menstruation). Hormonal shifts during this time can affect neurotransmitters, increasing the risk of mood disorders.

Postmenopause is a stage lasting roughly a third of a woman's life

Postmenopause is the final stage of menopause, occurring once a woman hasn't had any vaginal bleeding for a full year. She is then considered postmenopausal for the rest of her life. While some of the intense symptoms she might experience during postmenopause will decline, her risk for certain conditions and diseases will increase.

Women are born with all the eggs they will ever produce in their lifetimes

Girls are born with an estimated 1 million to 2 million eggs in their bodies, but around 10,000 die monthly before girls hit puberty. Scientists have not yet figured out why there's such an excessive number of eggs prior to menstruation, but they've calculated that there are roughly 300,000 to 400,000 eggs left at puberty.

Perimenopause, which typically occurs in a woman's mid-40s, precedes menopause

Sometimes referred to as the menopausal transition, perimenopause often lasts around four years as the ovaries' production of the reproductive hormones progesterone and estrogen decline. It may be accompanied by mental and physical symptoms, including irregular periods, hot flashes, sleep issues, mood swings, and alterations to a woman's sex drive.

Menopause and perimenopause symptoms may affect both the mind and the body

Women going through these aging transitions may experience some common physical and mental symptoms to varying degrees, including hot flashes, bladder control issues, brain fog, and vaginal dryness. This article dives into some of the most common symptoms women might expect during perimenopause, plus what they can do to relieve them.

What is medical menopause?

Medical menopause is when menopause is induced from either surgery or medicine. Chemotherapy and radiation, as well as oophorectomy (a surgical procedure that removes the ovaries) and a radical hysterectomy can cause a woman to become menopausal. Women that go through medical menopause experience the same symptoms as women that experience natural menopause. Learn more about the medical condition here.

This is what happens to your body during menopause

The menopause transition may begin in one's mid-40s with erratic periods and a decrease in estrogen. It can trigger health complications, including hot flashes, palpitations, and elevated risks of osteoporosis.

Menopause hormone therapy infuses the body with estrogen after the body's natural levels drop

The treatments can treat symptoms like hot flashes and vaginal dryness at varying doses. Progestogen, another hormone, is also typically prescribed with estrogen because estrogen alone can thicken the uterus lining, which elevates the risk of developing endometrial cancer.

Treatment-induced menopause is menopause induced by surgery or medicine

Chemotherapy and radiation, as well as oophorectomy (a surgical procedure to remove one or both ovaries) and a radical hysterectomy, can cause a woman to become menopausal. Women who go through medical menopause experience the same symptoms as women who go through menopause caused by natural hormonal cycles.

Menopause is a hormonal transition point, like puberty

Yet menopause isn't talked about as much. In this podcast episode by Houston Methodist, a Texas-based hospital, the host speaks with a gynecologist with a specialization in menopausal medicine about what menopause really is, and how women and the people in their lives can navigate this next life stage.

Modern pregnancy tests detect a specific hormone in a woman's urine or blood.

Hair loss after childbirth happens because pregnancy hormones paused the normal hair shedding process during pregnancy, so the hair loss is actually your hair cycle 'catching up' with its normal process several months postpartum.

Privacy advocates warn menstrual cycle apps could put women at legal risk in certain states.

Women experience heightened bone loss after menopause

Both women and men begin to lose some bone density after age 35, on average. But, for the first decade after menopause, women lose bone more rapidly due to the significantly decreased levels of estrogen, putting women at heightened risk of osteoporosis and related bone fractures.

The word allergy is partly derived from the Greek word 'allos' for 'other'

For people with allergies, their immune systems recognize substances as a harmful "other"—cuing an inflammatory response. This podcast explores allergy details and related topics, including how scientists are interested in if the same allergic response mechanisms could underpin other health issues, including severe, painful symptoms around the time of menstrual cycles. Since estrogen acts on white blood cells called mast cells, which leads to the release of histamines—similar to what happens during allergic responses—an understudied question is whether the same process is fueling some of the uncomfortable symptoms around menstruation. An allergist guest notes this raises questions about if antihistamine medications like Pepsid might alleviate them, something that hasn't yet been explored in clinical trials.

There are multiple HRT options to treat menopause and perimenopause symptoms including hot flashes, vaginal dryness, and mood swings.

Common hormone therapies to treat menopausal symptoms

While there is no cure for menopause, there are ways to treat some of the intense symptoms women experience during perimenopause. There are two main hormone therapies used, one in the form of a pill, gel, or patch to treat symptoms like hot flashes, and another in the form of a cream or ring to treat symptoms like vaginal dryness. Read this article to learn more about the different hormone therapies available for menopausal women.

Early menopause, occurring before age 45, can be triggered by certain risk factors

Some potential causes of early menopause include autoimmune disorders, chemotherapy, smoking, and certain surgeries that cause the body to produce lower levels of estrogen and progesterone.

40% of women will have noticeable hair loss by age 50.

Pregnancy causes a woman's blood volume to increase by up to 50%.

A 40-something science journalist was getting more winded during workouts, and experiencing night sweats, forgetfulness and tiredness—she thought it was perimenopause, but these common symptoms turned out to be signs of her blood cancer.

'Menobelly' is real, with more fat stored around the abdomen as estrogen levels drop.

Menopause can exacerbate anxiety

Some research shows that menopause can fuel anxiety and also that preexisting anxiety can boost the chances of experiencing other menopause symptoms, including hot flashes, insomnia, and brain fog. But treatments—including hormone replacement therapy, breathing exercises, and other forms of exercise—can alleviate some of these symptoms.

Telogen effluvium is a common, temporary type of hair loss that can be triggered by severe stress, illness, or other body changes like childbirth—it pushes as much as 70% of hair into its resting phase, causing hair to fall out.

A baby's due date is calculated from the first day of the last menstrual period—not when sexual intercourse occurred.

Only about 0.0001% of sperm, on average, successfully reach the uterine cavity

We've evolved to make pregnancy a complex and difficult process. From the initial development of the blastocyst, to the energy and nutrients needed to grow a new human, our bodies are both fighting and supporting fetal development.

By 2030, roughly 6% of the world's population will be in menopause

An estimated 25 million women pass through menopause annually, with a projected increase in the number of women in menopause in both lower-resource and higher-income populations in the years ahead, highlighting the social and economic value of focusing on menopause care.

Some female tardigrades reabsorb their eggs if no male fertilizes them

The eggs are laid in skin that has detached after molting. These species undergo sexual reproduction, but others reproduce asexually, with females producing clones from unfertilized eggs. Some hermaphrodite species have both male and female reproductive organs and can self-fertilize.

Mifepristone, approved in 2000, is used to end early pregnancies

The drug works by blocking progesterone, a hormone that is needed to support pregnancy. Mifepristone is typically used in combination with a second drug, misoprostol, because this regimen often causes less cramping and bleeding than just using misoprostol alone.

The hidden effects of March Madness

March Madness isn’t just a major sporting event—it’s also peak season for vasectomies. Urologists report a 50% increase during the tournament, as patients use recovery time as an excuse to watch nonstop basketball. Meanwhile, workplace distractions from bracket pools and game streaming are estimated to cost US businesses $17 billion.

Menopause affects the brain in complex ways

Lisa Mosconi, a neuroscientist studying the impact of menopause on the brain, explains in this video how menopause directly impacts a woman's brain health and explores why this is an important and often overlooked area in menopause and women's aging healthcare discussions.

Female Anopheles mosquito bites are the primary way malaria spreads.

What to know about early and premature menopause

Although it's rare, some women may experience menopause early. Early menopause describes women that are menopausal between the ages of 40 and 45. Women that go through menopause before age 40 experience premature menopause. Early experiences of menopause impact under 6% of women, and doctors can’t point to a specific reason why it happens. Learn about what we do know about the conditions here.

Estrogen is a really important hormone for men, too.

Blood moons only occur during total lunar eclipses, when the Earth blocks the sun, but its atmosphere lets redder parts of sunlight through to reflect off the lunar surface.

Why we should care about renaming the hormonal disorder PCOS to PMOS

The new name, polyendocrine metabolic ovarian syndrome, nods to the hormonal disruptions that cause this condition, which affects roughly one in eight women. People with PMOS may have symptoms including irregular periods, trouble conceiving, weight gain, acne, undesired hair growth, and more. The earlier name, polycystic ovary syndrome, was a misnomer because women with the condition don't have cysts in their ovaries. Rather, they have masses that are actually immature follicles. World health experts think the condition often goes undiagnosed.

Perimenopause can last as long as 8 years

Perimenopause typically lasts about four years, beginning at around age 45; however, some women experience it as early as their 30s. Smoking and thyroid disease are factors that can trigger early perimenopause. Early menopause, which can increase health risks, occurs in about 5% of women. Researchers are still investigating why it occurs.

Although the moon passes between the sun and Earth each month, its orbit is tilted by five degrees, preventing Earth from experiencing a solar eclipse each month.

Understand the complex, biological journey of pregnancy with this science explainer.

Menopause, once not discussed in polite company, is now a plot point in some television shows

Menopause has long been a topic left out of film and TV. But some shows, like "The Change," and celebrities, like Jennie Garth, are now openly talking about it. This article breaks down how Hollywood is starting to come around to the menopause conversation and how celebrities are talking about their own personal experiences, as well as advocating on Capitol Hill.

Women are four times as likely to be diagnosed with seasonal depression

This prevalence trend mirrors the broader incidence of depression among women and is well-documented. Researchers suggest the disparity stems from differences in hormones, social role expectations, coping mechanisms, and more. Men may also present with depression differently, and seek help less.

Scientists have not yet answered what the evolutionary benefit may be of menopause

Few animals are known to experience menopause, raising questions about why it would be evolutionarily advantageous to have women survive past their reproductive years. One leading hypothesis is the grandmother hypothesis—older women and other species known to experience menopause, like whales, can aid families and pass down knowledge to future generations.

Fetal development, week by week

Gestation is the period of time between conception and birth when a baby grows inside the mother's womb. Changes occur constantly over the course of these 40 weeks. At week 17, for instance, the skeleton of a fetus begins changing from soft...

The gaps in menopause research and their effects

Nearly all studies (99%) researching the biology of aging don’t consider menopause in their setup. A Harvard professor noted that about 75% of aging-related diseases are likely influenced by menopause. In this article, she discusses how gaps in research are negatively impacting how the medical system can effectively treat aging women. Read her analysis of the issue here.

Every eclipse is preceded or followed by another eclipse, separated by about two weeks and alternating between solar and lunar types.

It's never too late to start hormone replacement therapy for menopause symptoms because the products may help alleviate symptoms of menopause or fight bone loss.

Blood clotting is critical to maintaining life, but dysfunctional clots can be fatal.

A step-by-step overview of the IVF process

In-vitro fertilization involves a sequence of complex steps to move from egg production to birth. This include stimulating egg production in the ovaries, egg harvesting and fertilization outside the body, embryo culturing and transfer, and methods to support in and increase the likelihood of full-term pregnancy.

Humans aren't the only mammals who go through menopause, but it's rare in the animal world

While scientists are unsure how many mammals actually experience menopause, they do know for sure that humans aren't the only ones. Orcas and some toothed whales (like belugas and narwhals) go through menopause. And a recent study found chimpanzees also experience the condition, though it's late in life.