You probably know that having high cholesterol puts you at risk for serious health problems. A heart attack and stroke are among them. However, do you know what causes high cholesterol? What things in your life can affect your cholesterol level? Some things can't be changed. Others can. Knowing what's behind high cholesterol may help you stay healthy. Your Diet Your liver creates cholesterol on its own. Still, some of the cholesterol in your blood is the result of foods you eat. Foods high in saturated fat and trans fat can raise your levels of LDL (low-density protein) cholesterol. That's the "bad" kind. Most of the saturated fat people eat comes from animal-based foods. These include full-fat milk, cheese, butter, and other high-fat dairy products. Red meat, chicken and turkey with skin are other examples. A few plant-based foods also contain saturated fats. Coconut oil, palm oil, and cocoa butter are three of them. Trans fats have been common in packaged and processed foods, including some baked goods. They make these foods last longer. The source of artificial trans fats in these foods is partially hydrogenated oil (PHO). However, the Food and Drug Administration (FDA) has banned PHOs from processed foods starting in 2018. The FDA believes PHOs are not safe because of their link to heart disease. Your Weight Being overweight or obese increases your risk of developing high cholesterol. Extra pounds raise LDL levels. They also lower your HDL (high-density lipoprotein) level. That's the heart-healthy "good" type. Obesity also increases your total cholesterol level. It's not just pounds that make a difference. Your waist measurement can have an effect, too. The larger your waist, the more likely you are to have high cholesterol. (If you measure, do it just above your hip bones.) Men should try to keep their waist smaller than 40 inches. Women should aim for less than 35 inches. Your Exercise Habits Your risk of cholesterol problems is greater if you're a couch potato. Regular exercise helps shed extra pounds. That helps you maintain a healthy body weight. Not getting enough physical activity means your weight and your cholesterol levels will probably go up. Your Family History and Other Personal Factors High cholesterol runs in families. Even if you exercise regularly and eat well, you could have high cholesterol if it's hereditary. Also, an extreme example is a condition called familial hypercholesterolemia. It causes very high levels of LDL starting at birth. It can cause heart attacks in people who are very young. In general, everyone's risk of high cholesterol goes up with age. Men have a greater risk of high cholesterol than women until women reach age 55. From then on, the risk is equal for men and women. Also, Hispance American men are more likely to have high cholesterol than white or black men in the United States. Other Medical Conditions Other conditions that increase your chances of developing high cholesterol include: Diabetes that isn't well managed. Diabetes allows sugar (glucose) to build up in your blood. High levels of blood glucose cause high levels of LDL and low levels of HDL cholesterol. Too much sugar in the blood also hurts the cells that line your arteries. Kidney disease Polycystic ovary syndrome Pregnancy Underactive thyroid gland (hypothyroidism) Also, some medicines raise cholesterol levels as a side effect. These include some beta blockers, antidepressants, birth control pills and diuretics (water pills). Being a Smoker Smoking doesn't increase levels of LDL cholesterol. However, experts believe it lowers those good HDL levels. Smoking also hurts the walls inside your blood vessels. This allows cholesterol and other fats to build up inside them. That can cause blockages, which can result in heart attack or stroke.