Cholesterol is a waxy substance. Your body needs it to stay healthy. But too much can cause problems. It travels in your blood through the blood vessels. If you have a lot of cholesterol in your blood, it can build up along the walls of the blood vessels. This makes the vessels narrower and decreases blood flow. You are then at greater risk of a heart attack or a stroke.

Cholesterol is a type of lipid. Lipids are fats. Blood is mostly water. Fat and water don't mix. So lipids are carried in the blood inside a protein shell. These are called lipoproteins. There are two main kinds of lipoproteins:

• LDL (low-density lipoprotein). This is known as bad cholesterol. It mainly carries cholesterol to body cells. Excess LDL will build up on artery walls. This raises your risk for heart disease and stroke.
• HDL (high-density lipoprotein). This is known as good cholesterol. This protein shell collects excess cholesterol that LDL has left behind on blood vessel walls. That's why high levels of HDL can lower your risk of heart disease and stroke.

Total cholesterol includes LDL and HDL cholesterol, as well as other fats in the bloodstream. If your total cholesterol is high, follow the steps below to help lower your total cholesterol level:

• Cut back on saturated fats and trans fats. A diet that's high in these fats raises your bad cholesterol. Trans fats are also called partially hydrogenated oil. Choose lean cuts of meat and low-fat dairy. Use oils instead of solid fats. Limit baked goods, processed meats, and fried foods.
• Eat about 2 servings of fish each week. A serving size is about 3.5 ounces. Good choices include salmon, herring, tuna, sardines, or mackerel. The fish should not be fried. Most fish contain omega-3 fatty acids. These help lower total blood cholesterol. Omega-3 fatty acids lowers triglyceride levels, another form of fat in the blood. If you are pregnant, planning to be pregnant, or are breastfeeding, talk with your doctor for advice. Ask about the best fish choices and how much is safe to eat.
• Eat more whole grains. Eat soluble fiber, such as oat bran. These lower overall cholesterol.

Moderate physical activity has been shown to raise high-density lipoprotein (HDL) cholesterol, the good cholesterol. That's one of the many reasons regular physical activity can help keep you healthy.

• If you haven't been exercising regularly, start slowly. Check with your doctor to make sure the exercise plan is right for you.
• Choose a physical activity you enjoy. Walk, swim, or ride a bike. These are all good ways to be active.
• Start at a level where you feel comfortable. Increase your time and pace a little each week.
• Work up to 30 to 40 minutes of moderate to high intensity physical activity at least 3 to 4 days per week.
• Remember, some activity is better than none.

Quitting smoking, vaping, or using other tobacco or nicotine products can improve your lipid levels. It also lowers your risk for heart disease and stroke.

If you are overweight, your doctor will help you to lose weight. They will help you lower your BMI (body mass index) to a normal or near-normal level. Making changes in your diet and increasing physical activity can help.

Many people need medicine to help their cholesterol levels. Medicine to treat high cholesterol is effective and safe. But keep in mind that medicine does not take the place of exercise and eating healthy foods. All of these things work together. Your doctor can tell you if you may need a medicine to help lower your cholesterol.