The W.H.I. trial measured the most severe, life-threatening outcomes: breast cancer, heart disease, stroke and clots, among others. But for a woman who is steadily losing hair, who has joint pain, who suddenly realizes her very smell has changed (and not for the better) or who is depressed or exhausted — for many of those women, the net benefits of taking hormones, of experiencing an improved quality of life day to day, may be worth facing down whatever incremental risks hormone therapy entails, even after age 60. Even for women like me, whose symptoms are not as drastic but whose risks are low, hormones can make sense. “I’m not saying every woman needs hormones,” Rubin says, “but I’m a big believer in your body, your choice.”
Conversations about menopause lack, among so many other things, the language to help us make these choices. Some women sail blissfully into motherhood, but there is a term for the extreme anxiety and depression that other women endure following delivery: postpartum depression. Some women menstruate every month without major upheaval; others experience mood changes that disrupt their daily functioning, suffering what we call premenstrual syndrome (PMS), or in more serious cases, premenstrual dysphoric disorder. A significant portion of women suffer no symptoms whatsoever as they sail into menopause. Others suffer near-systemic breakdowns, with brain fog, recurring hot flashes and exhaustion. Others feel different enough to know they don’t like what they feel, but they are hardly incapacitated. Menopause — that baggy term — is too big, too overdetermined, generating a confusion that makes it especially hard to talk about.
No symptom is more closely associated with menopause than the hot flash, a phenomenon that’s often reduced to a comedic trope — the middle-aged woman furiously waving a fan at her face and throwing ice cubes down her shirt. Seventy to 80 percent of women have hot flashes, yet they are nearly as mysterious to researchers as they are to the women experiencing them — a reflection of just how much we still have to learn about the biology of menopause. Scientists are now trying to figure out whether hot flashes are merely a symptom or whether they trigger other changes in the body.
Strangely, the searing heat a woman feels roaring within is not reflected in any significant rise in her core body temperature. Hot flashes originate in the hypothalamus, an area of the brain rich in estrogen receptors that is both crucial in the reproductive cycle and also functions as a thermostat. Deprived of estrogen, its thermostat now wonky, the hypothalamus is more likely to misread small increases in core body temperature as too hot, triggering a rush of sweat and widespread dilation of the blood vessels in an attempt to cool the body. This also drives up the temperature on the skin. Some women experience these misfirings once a day, others 10 or more, with each one lasting anywhere from seconds to five minutes. On average, women experience them for seven to 10 years.
What hot flashes might mean for a woman’s health is one of the main questions that Rebecca Thurston, the director of the Women’s Biobehavioral Health Laboratory at the University of Pittsburgh, has been trying to answer. Thurston helped lead a study that followed a diverse cohort of 3,000 women over 22 years and found that about 25 percent of them were what she called superflashers: Their hot flashes started long before their periods became irregular, and the women continued to experience them for as many as 14 years, upending the idea that, for most women, hot flashes are an irritating but short-lived inconvenience. Of the five racial and ethnic groups Thurston studied, Black women were found to experience the most hot flashes, to experience them as the most bothersome and to endure them the longest. In addition to race, low socioeconomic status was associated with the duration of women’s hot flashes, suggesting that the conditions of life, even years later, can affect a body’s management of menopause. Women who experienced childhood abuse were 70 percent more likely to report night sweats and hot flashes.
Might those symptoms also signal harm beyond the impact on a woman’s quality of life? In 2016, Thurston published a study in the journal Stroke showing that women who had more hot flashes — at least four a day — tended to have more signs of cardiovascular disease. The link was even stronger than the association between cardiovascular risk and obesity, or cardiovascular risk and high blood pressure. “We don’t know if it’s causal,” Thurston cautions, “or in which direction. We need more research.” There might even be some women for whom the hot flashes do accelerate physical harm and others not, Thurston told me. At a minimum, she says, reports of severe and frequent hot flashes should cue doctors to look more closely at a woman’s cardiac health.
As Thurston was trying to determine the effects of hot flashes on vascular health, Pauline Maki, a professor of psychiatry at the University of Illinois at Chicago, was establishing associations between hot flashes and mild cognitive changes during menopause. Maki had already found a clear correlation between the number of a woman’s hot flashes and her memory performance. Maki and Thurston wondered if they would be able to detect some physical representation of that association in the brain. They embarked on research, published last October, that found a strong correlation between the number of hot flashes a woman has during sleep and signs of damage to the tiny vessels of the brain. At a lab in Pittsburgh, which has one the most powerful M.R.I. machines in the world, Thurston showed me an image of a brain with tiny lesions represented as white dots, ghostlike absences on the scan. Both their number and placement, she said, were different in women with high numbers of hot flashes. But whether the hot flashes were causing the damage or the changes in the cerebral vessels were causing the hot flashes, she could not say.