How Your Body Changes in Your Forties and What It Means for Your Health
As your 40th birthday approaches, you may feel apprehensive about aging. Body changes at 40 in women are often related to perimenopause (the transition into menopause), during which hormones like estrogen and progesterone start to fluctuate.
“Forty sounds like a magic number, but it isn’t exactly — everybody goes through their own changes on their own timeline,” says Nora Lansen, MD, a family practitioner, menopause expert, and the chief medical officer of Elektra Health, a digital platform for menopause care.
The changes detailed below may sound like a lot to deal with, but they are manageable with lifestyle changes, stress management, and medical treatment, if needed.
Physical Changes
Body changes in women at 40 typically arise from declining levels of estrogen. The most common and noticeable physical changes for women over 40 are weight gain, skin changes, and fatigue, says Deepa Iyengar, MD, a family medicine doctor and a professor at McGovern Medical School at UTHealth Houston. But fading estrogen can lead to other symptoms, too.
Weight Gain
As hormones fluctuate in your forties, your metabolism changes, often causing weight gain. This can happen even if you follow the same diet and exercise habits you did before 40, says Dr. Iyengar.
Fat deposits not only grow but can also shift location to the waist. “It's not just the numbers on the scale — we notice we're getting a little thicker around the middle,” says Dr. Lansen, who says this also increases risk of cardiovascular disease.
Muscle Loss
Starting at 40, muscle mass and overall strength declines by 8 to 15 percent per decade. As with metabolic changes, estrogen shares responsibility for muscle loss after 40. But muscle loss in women may also come from falling testosterone levels, says Lansen.
Skin Changes
Skin changes in your forties often start with wrinkles and fine lines from the loss of collagen and skin elasticity, says Iyengar. You may also notice sudden flushing, which happens in about 75 percent of women going through perimenopause.
Your skin may feel a little saggier and drier, which comes with falling estrogen levels, says Lansen. Many women in this age group also report new skin diagnoses like eczema and allergic dermatitis. Some women in their forties notice age spots, but these happen more often after 50. If you notice a new skin discoloration, let your provider know.
Thinning Hair
Hormonal changes can affect your hair follicles — structures in your skin that grow hair. This can cause your hair to get thinner, lose volume, or change texture, but not all women experience this.
“It’s not the same as male pattern baldness, but we do notice some hair loss, particularly at the crown of the head,” says Lansen, who adds that thinning hair can be genetic, from aging, or from hormone changes.
Joint Pain
Estrogen helps the fluid and cartilage at your joints cushion your bones, so when this hormone dips in your forties, joint cushion can lessen, causing pain. Studies show back pain, joint stiffness, and bone pain happen most often in women with a higher BMI.
Vision Changes
As hormones fluctuate throughout adult life, women often experience vision changes like dry eyes and blurry vision. After 40, estrogen and progesterone levels change, causing these symptoms more often.
Changes in Bladder Control
Declining estrogen doesn’t just weaken skeletal muscles — it can do the same to the muscles of your pelvic floor. This lower muscle tone can make it harder to hold in urine, especially when you cough or sneeze. “[Urinary incontinence] doesn't necessarily happen to everybody, but it does happen to a number of people,” says Lansen. Women who have experienced pregnancy are more likely to have these leaks as they age.
Fatigue and Sleep Challenges
Women going through perimenopause often experience new sleep disturbances, like insomnia, sleep-related breathing disorders like sleep apnea, and movement disorders like restless legs. The culprits in these sleep challenges are — once again — estrogen and progesterone, which also affect sleep quality.
Hot flashes and night sweats can steal your sleep, too, and missing sleep can lead to daytime fatigue. “For people who have been great sleepers their whole lives, suddenly they might notice that insomnia is setting in, leaving them feeling lethargic, dragging their feet, and feeling low motivation,” says Lansen.
Brain Fog
Studies continue to uncover more evidence that declining estrogen can affect how well your brain works, and many women experience brain fog, affecting learning and memory. Issues with brain function can also happen alongside other symptoms of midlife, like depression and sleep problems.
Brain fog can feel scary, says Lansen. “But it tends to recover after menopause.”
Hormonal Changes
In your forties, estrogen, progesterone, and other hormones wildly fluctuate before your final period, says Lansen. Although hormonal changes can cause many of the physical symptoms listed above, they also come with symptoms related to the hormones themselves.
Irregular Periods
As you head into your forties, your periods can become irregular and unpredictable, both in timing and flow. You may notice longer times between periods, or skip some altogether. Menstrual flow can become lighter or heavier, and one study found heavy periods in this time are linked with higher levels of fatigue.
Hot Flashes and Night Sweats
Hot flashes, a classic menopause symptom, can actually start earlier, in your forties. These episodes feel like sudden overwhelming warmth in your body, and typically last a few minutes. You may also notice night sweats, which happen when you have hot flashes during sleep.
Decreased Libido and Vaginal Dryness
As your hormones fluctuate, you may find you have less interest in sex. And when low hormone levels cause vaginal dryness, this uncomfortable symptom can cause pain during sex and lower your libido even more.
Mood Changes
In your forties, you may notice your mood changes and you feel more irritable, says Iyengar. Some women also experience more anxiety or depression.
One study found women in perimenopause experienced the highest level of stress and were more likely to report feeling anxious or depressed. “Midlife is a busy time. You may have kids, a partner, a job, or aging parents — there is a lot going on. And so stress layered on top of real physical changes is overwhelming,” says Lansen.
How Do These Changes Affect Your Health?
A decline in hormones can cause more than uncomfortable symptoms — it can also increase your risk for some health conditions, like heart disease and diabetes.
“We have found estrogen confers some protection against cardiovascular aging. And so once the estrogen declines, we catch up with the men and can develop atherosclerosis,” says Lansen, which describes the buildup of plaque in your arteries, increasing the risk of heart attack or stroke.
Besides cardiovascular effects, low estrogen can cause bone loss and pave the way for osteoporosis, a disease that weakens the bones and increases your risk for fractures. With declining hormone levels, you may also experience more urinary or vaginal infections.
On top of everything else, the loss of estrogen can increase your risk for type 2 diabetes because of decreased insulin sensitivity, weight gain, and fat redistribution.
How to Manage These Changes
While all these symptoms may sound dire, many women don’t experience them all, and you have plenty of options to lessen not only the discomfort from aging in your forties, but also to lower your risk of health conditions from hormone changes.
Lifestyle Changes
You can combat the negative effects of perimenopause through several lifestyle factors like diet, exercise, sleep, and skin care.
Follow a healthy diet. It’s important to eat a fiber-rich diet, and to include whole grains and plenty of fruits and vegetables. The Mediterranean diet can be a great approach. Try to avoid alcohol and caffeine, especially if they trigger hot flashes. Instead, focus on unprocessed foods and stay hydrated, says Iyengar. These dietary changes can lessen perimenopause symptoms and help prevent heart disease and diabetes.
Move your body every day. Regular physical activity can help you prevent weight gain, boost your sleep quality, strengthen your bones, and help you feel happier. “The longer we stay stagnant, the harder it is to get moving,” says Lansen. Try to exercise for 30 minutes a day, but not too close to bedtime.
Prioritize sleep. You can boost your sleep quality and quantity by following good sleep hygiene habits. For your best sleep, keep a regular sleep routine and schedule, avoid caffeine and alcohol before bed, and keep your sleep space cool, dark, and quiet.
Try Kegels. “Pelvic physical therapy is a great way to counteract age-related incontinence, because it helps to re-tone the pelvic floor,” says Lansen. Kegel exercises strengthen your pelvic floor muscles, and you can do these discreet movements wherever you are. To try Kegels, imagine stopping the flow of urine mid-stream by squeezing those muscles. Hold for a few seconds, relax, then repeat.
Moisturize often. For dry skin, skip the soap, washing with a mild cleanser instead. Use moisturizer right after a bath or shower, and throughout the day if your skin feels dry. You can also try a moisturizer with hyaluronic acid or glycerin for stubborn dryness.
Find your community. Whatever health changes you experience in your forties, you are in good company. It can help to share your symptoms with others going through the same thing, and stave off isolation by staying close to family and friends, says Lansen.
Stress Management
Your forties often come with increased stress, but you can take steps to lessen it. “I think it's important to do the things that make us happy,” says Lansen, like finding hobbies and getting together with friends.
“Keeping yourself moving is one of the best ways to alleviate stress,” says Lansen, who recommends moving your body throughout the day, even if it’s just at home.
You can also try relaxation techniques like mediation, yoga, and deep breathing exercises, which can not only squash stress, but may also decrease perimenopausal symptoms.
Sexual Health Tips
For women in their forties experiencing low libido and other sexual issues, many options are available — now more than ever. “For vaginal dryness, I recommend starting with a vaginal moisturizer that you can get over the counter,” says Lansen.
You can use water-based vaginal lubricants like K-Y Liquid and Astroglide, or moisturizers like Replens and Vagisil. Try not to pick products with glycerin, which can cause irritation. “Pelvic physical therapy also works great for someone who's having discomfort with sex,” says Lansen, who adds vaginal estrogen is also a common treatment for vaginal dryness.
When to See a Doctor
You can see your healthcare provider at any time to ask questions about body changes in your forties. “Regular doctor visits are important to make sure you are up to date on your preventive and gynecological screenings,” says Iyengar.
It’s especially important to see a provider if you experience the following:
Symptoms that interfere with your well-being
Extremely heavy bleeding (changing tampons every hour or two for two or more hours)
Bleeding that lasts longer than seven days
Bleeding between periods
Frequent short cycles (periods fewer than 21 days apart)
Seek out a provider you trust and who stays up to date on the latest treatment options for perimenopause, says Lansen, adding, “As with any treatment option and any set of health concerns, individualized care is critical.”
Depending on your symptoms and health history, your provider may recommend hormone replacement therapy, but adding more estrogen isn’t always the answer. “In terms of just replenishing or boosting estrogen levels, it doesn't always fix everything,” says Lansen, and some women, like those with a history of breast cancer, may not be eligible for estrogen therapy.
“I always recommend optimizing the basics first and foremost with sleep, nutrition, exercise, and meditation,” says Lansen. But if symptoms persist, your provider may suggest trying hormone therapies like estrogen and progesterone, or hormone-free medications.
The Takeaway
For women, body changes at 40 originate from fluctuating hormone levels, and may include weight gain, muscle loss, dry skin, thinning hair, sleep issues, and brain fog.
Changing hormones can also cause decreased libido, vaginal dryness, mood swings, hot flashes, and irregular periods.
You can lessen these symptoms through lifestyle habits like a healthy diet, regular exercise, and good sleep habits.
Let your healthcare provider know if your symptoms bother you — they can help you create a treatment plan to get you feeling better.
