As you age, you experience significant change in the levels of many hormones, most notably estrogen and progesterone as a result of perimenopause and menopause. A decline in testosterone, however, is solely related to age rather than menopause and can begin far before perimenopause, resulting in changes in libido, as well as bone and muscle mass.

Sitting down too much can have many negative consequences for your health, such as high blood sugar, high blood pressure, abnormal cholesterol and excess body fat around the waist, so it’s important to keep yourself moving throughout the day. Even if you’re stuck at home, there are plenty of workout apps and online classes for exercise. Even taking a simple walk outside can change your life.

The average woman’s fertility begins to decline in her 30s, particularly after the age of 35. By the age of 40, a woman’s chance of getting pregnant within one menstrual cycle is less than 5% and most women lose their ability to have a successful pregnancy during their mid-40s.

If you do go through a pregnancy after the age of 40, it’s important to be aware of the risks of childbearing in that age range. One German study found that, while preeclampsia, gestational diabetes and pregnancy-associated hypertension occurred with more frequency in women above the age of 40, with proper healthcare and monitoring, pregnancy and childbirth outcomes did not have much difference from those in younger women.

Perimenopause, the transitional time when the changes of menopause start, typically begins during a woman’s 40s and lasts about a year, although it can last six years or more. Perimenopause typically means irregular periods, as well as hot flashes, vaginal dryness and problems with sleeping.

While the average age for women in the developed world going through menopause is 51, most women experience it between the range of ages 40 and 58. Women going through menopause experience changes in hormone levels, physical changes affecting their sex organs and sexuality, and changes in weight and fat distribution.

It’s important to cultivate meaningful relationships, especially as you get older, because loneliness has been scientifically proven to be harmful to your health. One study published by the Journal of the American Medical Association found that lonely older adults were more likely to experience functional decline and had an increased risk of death.

As you get older and closer to the time of menopause, you have an increased likelihood of finding lumps in your breasts. While these are typically non-cancerous, lumps on and around the chest do sometimes end up being commonly missed symptoms of dangerous disease. Risk of breast cancer does increase with age, so it’s important for women ages 40 and older to have a mammogram done once every one or two years.

How much sleep you need every night changes as you age, and it’s important to make sure you’re getting enough. One survey conducted by the Centers for Disease Control and Prevention’s National Center for Health Statistics found that postmenopausal women between the ages of 40 and 59 had more trouble falling asleep and staying asleep than premenopausal women and were also more likely to wake up not feeling well-rested.

Heart disease is the leading cause of death among both men and women in the United States, causing about 1 in 5 female deaths. Heart disease risk increases with age, and heart attacks are much more likely to occur in women once they’ve reached the age of 50. One recent study even found that half of women with heart failure get the wrong treatment, so it’s more important than ever to make sure you take care of your cardiovascular health.

Heart attack symptoms can differ between men and women, particularly symptoms that occur at the onset. While chest pain or discomfort is the most common symptom for all people, women are more likely than men to experience symptoms such as nausea or vomiting, back or jaw pain and shortness of breath.

It’s important for your own health to have a good relationship with your doctor, and there are many factors you may consider in choosing the right one, including gender. According to a study published in Proceedings of the National Academy of Sciences, women are more likely to die after suffering a heart attack if their physician is a man. Researchers found that this may be due to male physicians struggling to communicate and advocate for female patients, which leads to less adherence to preventive care.

Women have a higher risk of osteoporosis, a condition in which the bones become weak or brittle, and that risk increases with age. About 10 million Americans have osteoporosis, and approximately 80% of them are women. About 1 in 2 women over the age of 50 will break a bone as a result of osteoporosis, and a woman’s risk of breaking her hip is the same as the combined risk of getting breast, ovarian and uterine cancer.

Your skin can tell you a lot about your health, and it’s important to manually inspect your skin at least once a month for signs of skin cancer. It’s also a good idea to get a skin cancer screening by a healthcare provider, in which your skin is checked for birthmarks, moles and any other unusual marks or signs of cancer.

It is recommended that people age 45 or older get routinely tested for Type 2 diabetes, so make sure to speak with your doctor about a blood test.

As the body transitions into menopause, it also produces less estrogen, which results in the loss of breast tissue, fat and mammary glands. As a result, the breasts become less full and can also sag due to connective tissue losing its elasticity.

Even if you are taking care of your hair hormone shifts as a result of menopause result in about half of women experiencing some degree of hair thinning before they turn 50.

As you age, you may experience hair loss, or alopecia. About a third of women deal with alopecia at some point in their life, and up to two-thirds of postmenopausal women deal with hair thinning and bald spots. These can, in turn, greatly affect their happiness and emotional well-being.

Handwashing is an important habit to instill from childhood, and it’s vital to health and hygiene throughout your life. Keep yourself from getting sick by making sure to wash your hands before and after eating, after going to the bathroom and after touching garbage, among other things.

Smoking tobacco puts you at risk of many health issues, including heart disease, tooth loss, gum disease, cataracts, diabetes and arthritis. Even if you’ve been smoking for years, it’s never too late to quit. Just one year after quitting, your risk of having a heart attack drops dramatically, and within two to five years, your risk of having a stroke can be reduced to about that of someone who never smoked. Those who quit also cut their risk for bladder, esophageal, mouth and throat cancer by half within five years, while the risk of dying due to lung cancer drops by half 10 years after quitting.

Even those who experience healthy aging deal with issues such as collagen loss. As you get older, your body produces less collagen, a protein that keeps the skin elastic and firm. The loss of collagen, therefore, tends to result in thinner and weaker skin.

Starting in your early 40s, there is a good chance you will begin to have problems with near vision, particularly in cases such as reading or working at a computer. According to the American Optometric Association, other common vision issues that come with age include difficulty seeing in the dark, issues with glare while driving and changes in how you see colors.

With age, women, in particular, tend to experience reduced tear production as a result of hormone changes. Because of this, you may experience dry eyes and irritation, which is an issue as tears actually keep your eyes healthy and help maintain clear vision.

Vaginal dryness is another issue that comes with age, occurring most frequently in older women after menopause, with the main cause being reduced estrogen levels. Vaginal dryness can cause discomfort and affect your sex life, so it’s important to address with your gynecologist as soon as you can.

Despite the issues that do come with menopause, one study published in the American Journal of Medicine found that sexual satisfaction in women increases with age, even if sexual activity decreased. It’s good to know that your romantic life doesn’t necessarily have to suffer.

You may already experience dry skin as the seasons change, but as you get older, you may deal with more dry spots on your skin, particularly on the lower legs, lower arms and elbows. Dry skin can also be caused by issues such as kidney disease and diabetes.

Uterine fibroids are quite common and can occur at any age, but there is an increased risk of getting them as you get older. Uterine fibroids, growths that occur on the walls of the uterus, are typically not cancerous or dangerous, but they do sometimes cause heavy bleeding, pain and issues with fertility or pregnancy.

As you get older, alcohol affects your body differently, and older women are particularly sensitive to its effects. Drinking too much alcohol can cause older adults to have issues with balance, resulting in falls and broken or fractured bones, or to become forgetful and confused. Many other health conditions are also worsened by drinking excess alcohol, such as diabetes, osteoporosis, cancer and liver damage, so the next time you’re fixing for a drink, perhaps consider making yourself a delicious mocktail instead.

While anyone of any age can be diagnosed with cancer, risk definitely increases with age. Make sure to keep an eye out for any unusual symptoms and get regular screenings, as 91% of new cancer diagnoses occur in people over the age of 45, according to the National Cancer Institute.

Working out is an important habit to have as you age, and it’s as vital to your mental fitness as it is to physical fitness. One study published in the journal Neurology found that women who had greater cardiovascular fitness in middle age had a lower risk of dementia later in life.

Older people experience a loss in sweat and oil glands, which can negatively affect the healing of skin damage and also cause overheating. This is important to keep in mind, especially since overheating can keep you from sleeping well on hot summer nights.

Skin tags — small, typically flesh-colored skin growths with a raised surface — become more common as people, particularly women, get older. Usually found on the neck, eyelids and body folds such as the chest, armpits and groin, skin tags are harmless, but you should make sure to talk to your doctor about any skin conditions you’re unsure of. Skin tags can become irritated, but luckily they can also be removed.

Changes in your hormones affect your muscle tone, so the muscles in your pelvis weaken as you get older. This includes the muscles that restrain your bladder, which can result in urinary incontinence. Older women are especially prone to decreased bladder control, so make sure to speak with your doctor about ways to prevent and treat any leaks.

A person’s immune system weakens as they age, which means the older you get, the more likely you are to get sick as the result of exposure to bacteria or a virus. Recovery can also take longer, so it’s more important than ever to take preventative care by taking up the habits of people who never get sick.

There are many myths about aging, but the fact that you tend to shrink in size as you do isn’t one of them. As you get older, the spaces between your joints become narrower and the discs between the vertebrae in your spine flatten. This, along with the fact that your muscles are losing mass, results in loss of height.

Weight gain in women can be caused by menopause, as well as simply the result of genetic factors or aging. This isn’t necessarily a bad thing, however; according to one study published in the Journal of the American Medical Association, older adults considered overweight according to the BMI scale live longer than their thinner counterparts, a fact that may be the result of extra pounds protecting the body against age-related diseases.

Stress can greatly affect your body in many ways, such as causing high blood pressure and heart disease and affecting your immune system. If you have health problems such as asthma and digestive disorders among others, stress can worsen them. There have even been some findings that high levels of stress can make you age faster. Work to mitigate your stress levels by taking care of yourself with exercise, relaxation and mindfulness.

Family dinners are a time-honored tradition, and for good reason. Americans eat more than half of their meals alone according to a report by research firm NPD, a practice that is not good for your health. According to a study published in the Nutrition Journal, people who eat alone tend to eat meals with less nutritional value, which can result in serious health problems as a result of an unhealthy diet.

Depression is a serious and difficult condition to deal with at any point in life. While it is common among older adults, however, it is not a normal part of aging, and it may be difficult to recognize due to the fact that symptoms differ with age. For example, sadness does not tend to be the main symptom. Instead, older people with depression tend to present with issues sleeping, irritability, tiredness, confusion and issues with attention.

More than anything, having fun and feeling fulfilled is the key to a healthy and happy life. Taking part in hobbies and social activities and taking the time to relax can have great effects on your health as you age. In fact, one study published in the Journal of Gerontology found that older adults who spent their time volunteering reported higher levels of well-being. Another study published in the New England Journal of Medicine found that leisure activities decreased risk of dementia, which is even more of a reason to pick up a fun new hobby after the age of 40.

More from The Active Times:

Simple Ways to Deal With Everyday Stress

35 Ways to Create a Healthier Home

How to Stretch Your Neck, Legs and Everything Else

Safe and Easy Workouts Perfect for Seniors

Unemployment Tips: Reignite Your Passion