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

Less than 1% of aging studies consider menopause and its effects

Nearly all studies researching the biology of aging don't consider menopause in their setup. In part, that's because menopause is difficult to emulate in animal models. Menopause is uncommon in the animal world beyond humans and whales. This presents a problem for medicine and science because about 75% of aging-related diseases are likely influenced by menopause.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Chimpanzees are dying from human colds

For some great apes, the threat of human-borne diseases outweighs poaching or habitat loss. This article details the danger of reverse zoonoses, which refers to diseases that spread from humans to animals.

Late-onset menopause lowers osteoporosis risks, but heightens the risks for certain cancers

Defined as when a woman starts to experience perimenopause after age 55, late-onset menopause is linked to an elevated risk of developing breast, ovarian, and uterine cancers.

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.

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.

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.

The purpose of narwhal tusks has mystified researchers for centuries

Nicknamed the "unicorn of the sea," narwhals have no teeth aside from two canines that grow directly forward as tusks. For roughly 85% of females, they stay embedded in the bone. For males, they grow into large, spirally tusks that are full of nerve endings and blood vessels. Scientists today believe that tusks likely formed for sexual selection purposes and eventually evolved to assist in other processes, such as hunting.

Over 200 known species hibernate, allowing them to lie dormant and survive harsh periods when water and food become scarce, such as frigid winter months or scorching summer periods.

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.

Humans are the only known reservoir of poliovirus

The virus has not been found in any other species, which makes humans the only known reservoir for polio. In laboratory settings, nonhuman primates have also been infected with the virus, but there's no evidence that they contract the virus in nature.

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.

27% of US menopausal women used estrogen in 1999, but by 2020 that number was under 5%

The fallout of studies in the early 2000s linking hormone therapy for menopause and elevated cancer, stroke, and other health risks meant that even decades later—yet before the FDA removed its black box warning in 2025—use of HRT remained extremely uncommon. (Some users may experience a paywall.)

Across the animal kingdom, parenting can include adults carrying their young, providing their bodies for sustenance, searching for food and shelter for their children, and separating siblings who may eat one another.

Menopause may become a $600B industry

Companies marketing products and supplements to alleviate menopause symptoms and make life easier during this life stage have become a gold mine. This 2022 article explores how and why companies have swooped into this space, and whether you should trust them or not.

Mammals gradually expanded in size and diversity after the dinosaur extinction

After an asteroid impact caused a mass extinction event 66 million years ago, small mammals were among the few surviving species. With fewer predators, mammals steadily grew larger as new habitats emerged.

Some animals, including certain tropical ants, have little or no microbial populations in their gut, upending the idea that all animals rely on this ecosystem to help maintain their health and proper functioning.

Health problems are being misdiagnosed as perimenopause symptoms

Symptoms of menopause and perimenopause (the premenopause period) can be varied enough that clinicians dismiss them in patients in their mid-30s and onward as just a symptom of hormone level change. In this story, a woman's itching was dismissed as a hormonal change, but after two years and 11 separate doctor consultations, was diagnosed as cancer. (Some users may experience a paywall.)

Can animals understand fairness?

Academics have long wondered if fairness is solely a concern of humans. In the largest meta-analysis to date, UC Berkeley researchers tested whether monkeys felt jealousy after receiving unequal rewards. The patterns showed low evidence for inequity aversion and instead frustration due to their expectations not being met by humans. These findings suggest that pursuing fairness and equality is uniquely human.

Stress affects different animals in different, but useful, ways

Animals feel stress when they experience actual dangers—such as a zebra chased by a lion. Humans often feel stress from worries, memories, or even thoughts about problems that may occur in the future. For this reason, animals tend to experience stress in short, intense bursts. Conversely, people can feel stressed for long periods, which can eventually be harmful to their health.

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.

Almost 80% of people diagnosed with autoimmune diseases are women

Yet it's still unanswered what may account for that difference. To better understand this disparity researchers are exploring factors including hormonal changes that occur around puberty, pregnancy, and menopause, as well as gut microbe differences, and aspects of X-chromosome protein-coding genes. (Some users may encounter a paywall.)

Why do humans have such long childhoods?

Humans have over twice as long childhoods than other animals with similar lifespans like whales and elephants. A human child can grow for nearly 20 years before they become a reproducing adult. Researchers believe there's a connection between long childhoods and human's unusually large brain size, though the science is not totally clear. Dive into what scientists know here.

Research shows that during total solar eclipses, some animals change their behavior to match their nighttime activities.

Environment and genetics explain why animals have widely different lifespans

Both environmental conditions and genetic factors shape how long various animals live. For some creatures, colder conditions allow for less energy use and slower aging. Larger animals have fewer predators. While humans don't live the longest, we are a rare species that successfully lengthened its average lifespan over time.

Animals get SAD—especially those in zoos, like pandas

Giant pandas in locations outside their evolved latitudinal range (from southeast Asia to northern regions around Beijing) exhibit more sluggish behavior, even when they were born there. Researchers have observed that similar sensitivities to "photoperiods" (or time with light) impacts many animals, including birds, insects, and our pets. (Nautilus imposes a metered paywall.)

Can humans delay or reverse old age?

We're not sure yet. Researchers at the University of California San Francisco are studying why some conditions and behaviors, such as low-oxygen environments and exercise, benefit the aging process, hoping to reveal potential health applications. Some of this research focuses on klotho, a naturally occurring age-regulating hormone named after the Greek Fate Clotho. Animal studies on klotho brain injections found subjects had improved memory recall and age-related degeneration resistance.

Dolphins have doulas too?

For the first time in over a decade, a dolphin gave birth at Brookfield Zoo, and she didn’t do it alone. Right beside her was another dolphin, acting as a doula. Why do dolphins support each other this way? The answer reveals something incredible about how animals care for one another.

The halting of human bone growth helps manage heat produced from metabolism

While fish, amphibians and reptiles get bigger throughout their lives until they die, their slower metabolisms allow their bodies to regulate the resulting smaller temperature increases. In humans, hormones triggered during puberty harden growth plates, ending bone lengthening.

Humanity's reduced body hair slows down wound healing

Cuts to human skin take twice as long to heal compared to chimps and other mammals. Scientists argue this is due to the reduced number of hair follicles on human bodies. Hair follicles contain stem cells which help repair skin cells faster, so as humanity shed its hair over time, so to speak, it also slowed its wound healing.

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

Once whale songs were discovered, conservation efforts boomed

Until the 1950s, humans believed whales were mute. Once American underwater surveillance systems caught their sounds during the Cold War, the perception of the creatures changed, leading humans to campaign for whaling bans and long-term conservation efforts. These captivating whale songs can be heard throughout the ocean.

Georges Cuvier used his knowledge of anatomy to prove extinction had occurred

Extinction had been viewed as impossible because a divine plan for the world would not rationally involve the loss of any of God’s creations. However, mammoth and mastodon bones differed from elephants’, and it seemed impossible that such creatures could be hiding elsewhere on Earth.

Human ancestors: a guide

Modern humans are not the only creatures classified as part of the Homo genus. This article examines the eight other humans that fall under the Homo umbrella.

Where are humans on the evolutionary tree?

This interactive tree-shaped map explores the evolutionary connections between more than two million species. According to this map, humans are on the same branch as great apes, tarsiers, and treeshrews. That branch then splits into even smaller branches, with humans appearing on the same twig-like branch as chimpanzees and bonobos.

Old Thom, the rare solitary orca

This orca has intrigued and perplexed scientists because of its seemingly docile existence separate from other orcas, which are known to be highly social beings.