You know the basics of heart disease: It’s the number one killer of women, you’re at risk if you have high blood pressure or cholesterol or both, and you can improve your odds by staying slim and exercising. But there are other factors that can damage your ticker that no one ever tells you about.

Warning Signs

It’s a common belief that everyone has chest pain during a heart attack. In real life, women may have less obvious symptoms and are as likely to have shortness of breath as chest pain. You also might feel pain in your jaw, back, or upper belly. And women also may feel nauseous, lightheaded, or dizzy.

Even thin women can be at risk

Yes, being overweight or obese is a major risk factor for heart disease. But "there are plenty of women walking around who are thin and have high blood pressure or elevated cholesterol," notes Dr. Goldberg. Sometimes it boils down to genetics—if high cholesterol or hypertension runs in your family, you’ll be more susceptible, too. You can also have a normal body mass index (BMI) but still have high amounts of visceral fat—the body fat stored deep within your abdomen that nestles around your liver, pancreas and intestines. This type of fat is considered particularly dangerous because it secretes cytokines, inflammatory substances that are toxic to your heart, explains Ian Neeland, MD, a cardiologist at the University of Texas Southwestern Medical Center in Dallas. A 2016 study found that people with greater increases in visceral fat over six years had more substantial elevations in metabolic risk factors, such as high blood sugar and high triglycerides, than those whose visceral fat stayed fairly stable. In fact, some cardiologists are now considering retiring the BMI entirely and just focusing on visceral fat as a barometer of heart disease risk, adds Dr. Neeland.

Technically, the only way to directly gauge your visceral fat is via abdominal CT or MRI, but these scans are not generally used for that purpose. Instead, “you can ask your primary care physician to measure your waist circumference,” says Dr. Neeland (or do it yourself). “A measurement higher than 35 inches suggests greater risk of heart disease.”

The Same but Different

Heart disease is the most common serious health issue among both men and women in the U.S., but it doesn't affect them the same way. Some heart conditions are more likely to happen in women, and symptoms of others can be different for the two genders. It’s important to know what to watch for and how to protect yourself as you get older.

SCAD

Spontaneous coronary artery dissection (SCAD) is when one of your heart’s blood vessels tears. That can slow down or block your blood flow and lead to intense chest pain and other symptoms that can feel like a heart attack. This is a serious condition that needs to be treated quickly. Women are more likely than men to have SCAD, especially if they’ve given birth recently.

Being depressed isn't great for your heart

This just in: Middle-aged women with depression are at higher risk of heart disease, suggests a study presented in 2016 at the North American Menopause Society’s annual meeting. Loneliness and social isolation are also linked to a 29 percent greater risk of a heart attack, according to a review of research published in April of 2016 in the medical journal Heart. There are a few theories as to why. Both conditions increase levels of stress hormones, such as cortisol and adrenaline, which can raise blood pressure and inflammation, points out Suzanne Steinbaum, DO, director of women’s heart health at Lenox Hill Hospital in New York City and a spokesperson for the American Heart Association’s Go Red for Women campaign. It may also be that people who are lonely and/or depressed are less likely to do things to look after themselves, like eat well, exercise, and take their medications, and more likely to smoke and drink excessive alcohol. Your doctor should screen you for depression at your annual physical; you should also be alert for symptoms of depression—such as feeling sad, anxious or irritable, and having trouble sleeping and concentrating—that last more than two weeks.

Your health during pregnancy is a clue

Did you have high blood pressure, preeclampsia, or gestational diabetes during pregnancy? Even if symptoms disappeared post-delivery, you’re still at greater risk of heart disease. According to a study published in June of 2016 in the journal Hypertension, pregnant women who experience even small increases in blood pressure during pregnancy may be at high risk of developing metabolic syndrome (a combination of heart disease risk factors, including a large waistline, low HDL cholesterol and high triglycerides, blood sugar, and blood pressure) after giving birth.

"Pregnancy is a stress test for your body—if you’re predisposed to heart disease, it may show up now, under the strain of weight gain and hormonal changes," says Deborah Kwon, MD, a cardiologist at the Cleveland Clinic. If you had one of the aforementioned conditions during pregnancy, make sure your primary care physician knows and gives you frequent cardiovascular health screenings.

Menopause

While they don’t cause heart disease, the natural changes that happen to your body during menopause can make you more likely to have it. Hormonal balance is essential as oestrogen can help maintain healthy arteries, but progesterone is needed to balance the effects of excess oestrogen and to support heart health. Blood pressure, belly fat, and LDL (or “bad” cholesterol) can go up after menopause, too and can all be helped with good progesterone levels.

Depression

This mental health condition can double your chances of heart disease, and women are twice as likely to have it as men. It can make you less likely to stay active and take care of your health, and ongoing stress and anxiety can put a strain on your heart. A combined cream such as 20-1 has been found helpful for depression by Jeffrey Dach, MD and progesterone alone such as in Serenity can help elevate mood.

Sleep matters

Sleep deprivation raises levels of cortisol and inflammatory cytokines, both of which promote the development of heart disease by increasing blood sugar levels and blood pressure, explains Dr. Goldberg. In fact, people who get five or fewer hours of sleep a night have 50 percent more calcium in their coronary arteries—an early marker of heart disease—than those who clock seven hours of slumber a night, according to a 2015 Korean study. Too much sleep may be a problem, too. The study found that folks who snoozed nine or more hours a night had 72 percent more coronary calcium than those who slept seven hours. It’s not just how much you sleep—it’s also how well you sleep. The same Korean study revealed that people who reported poor sleep quality had about 20 percent more calcium in their arteries than those who snoozed well. That’s no surprise, because people who toss and turn may have undiagnosed sleep apnea, which is also linked to heart disease, notes Dr. Goldberg. (According to some estimates, up to 26 percent of adults in the United States may suffer from this condition, which causes frequent interruptions in breathing during slumber.) If you’re spending plenty of hours in the sack but don’t feel well rested, ask your doc about a referral to a sleep specialist.

Nearly half of all heart attacks are silent

About 45 percent of heart attacks have such mild symptoms that they go unnoticed, according to a Wake Forest Baptist Medical Center study published in May of 2016. Researchers analyzed the medical records of nearly 9,500 middle-aged Americans—more than half of them women. They discovered that, over an average of nine years, while 386 patients had heart attacks with clinical symptoms, 317 had “silent” heart attacks, meaning the heart attacks were diagnosed after the fact, with tests like electrocardiograms, but weren’t acknowledged by the people themselves.

The take-home message? If you have risk factors (such as a family history of heart attack at a young age, high blood pressure, high cholesterol or type 2 diabetes) and experience subtle, vague symptoms like shortness of breath, back pain, jaw pain, nausea or fatigue, get checked out. “I had one patient whose jaw hurt every time she got on a treadmill,” says Dr. Steinbaum. “Once she stopped, her jaw pain would go away. Her dentist told her that her teeth were fine; it wasn’t until she ended up in my office that we made the connection to her heart.”

Diabetes

This condition also can double a woman’s chances of heart disease. One reason is that high blood sugar slows down the flow of oxygen in your blood and can lead to plaque buildup in your arteries. Another is that women with diabetes may be more likely to be obese and have high blood pressure and high cholesterol. You can manage your weight and blood sugar levels with diet and exercise.

The fitter you are in your forties, the better

Those in the best shape in the second half of their fifth decade were 37 percent less likely to suffer a stroke after age 65 than those in the worst, per a University of Texas Southwestern Medical Center study published in June of 2016. "Exercise is one of the best things you can do to prevent and combat cardiovascular disease," says Dr. Kwon. "People with coronary artery disease who exercise actually develop tiny bypass channels to get around the blockages that narrow their arteries." (Talk to your doc about what’s safe if you have heart disease.) And it’s never too late to start. Johns Hopkins research found that inactive folks who increased their physical activity after age 45 to reach 150 minutes of moderate or 75 minutes of vigorous activity per week reduced their risk of heart failure by 22 percent. Dr. Kwon’s recommendation: Grab your spouse (or a friend) and head out for a brisk half-hour walk. You’ll hit the sweet spot in terms of time versus benefit—and get some quality one-on-one while you’re at it.