Your arteries carry oxygen-rich blood from your heart to your entire body. When you're young and healthy, they're wide enough to allow the blood to flow through easily, and their walls are elastic, so they can expand and contract as needed.
But as you get older they might harden, as plaque -- made up of cholesterol, fat, calcium, and fibrous tissue -- builds up within them, narrowing the vessels. This process, called atherosclerosis, puts you at risk for heart attack, stroke, and peripheral artery disease. It begins much earlier than you might think.
"Atherosclerosis usually starts in the teens and 20s, and by the 30s we can see changes in most people," says cardiologist Matthew Sorrentino MD, a professor at The University of Chicago Medicine. In the early stages, your heart-related screening tests, like cholesterol checks, might still come back normal.
But over the years, this problem tends to slowly get worse. By the age of 40, about half of us have cholesterol deposits in our arteries, Sorrentino says. After 45, men may have a lot of plaque buildup. Signs of atherosclerosis in women are likely to appear after age 55.
Plaque is dangerous because it can break off and form a clot that blocks your artery and stops blood flow to your heart, brain, or legs. That might cause a heart attack, stroke, or gangrene.
Other Risk Factors
Your age isn't the only thing that can affect your arteries. Lifestyle matters, too. Extra weight, smoking, lack of exercise, and eating a lot of unhealthy foods can all take a toll.
Your family history plays an important role, too.
In the later stages of atherosclerosis, some people have chest pain, fatigue, or shortness of breath. But you might not notice any symptoms at all.
Your doctor can use the American Heart Association's risk calculator to estimate your odds of getting this condition, Sorrentino says. The calculator crunches a lot of info -- including your cholesterol, blood pressure, weight, and medical and family history -- to predict your chances of having an emergency like a heart attack or stroke in the next 10 years.
Read more on your risk of developing atherosclerosis.
Protect Yourself
While you can't change your age or your family history, you can take steps to help keep your arteries in good shape.
Get regular exercise, eat a balanced diet, drop extra pounds, and don't smoke, Sorrentino says.
Ask your doctor if you're at risk for atherosclerosis. They might recommend you take medication, usually a statin, to lower your chances of getting a heart attack or stroke.