context: You've probably heard that you need to watch your cholesterol to keep heart disease away. That's also true of heterozygous familial hypercholesterolemia. The disease can cause your cholesterol numbers to go way up. If your doctor tells you that you have it, it's important to get treatment to cut your chances of a heart attack or stroke. You don't catch He FH the way you might pick up a cold. It's a condition you're born with that was passed down to you from genes you got from your parents. Over time, your high cholesterol levels can damage your arteries -- vessels that carry blood and oxygen from your heart to the rest of your body. That raises your chances of a heart attack at a young age. Diet, exercise, and, most importantly, medicine, can bring down your levels of cholesterol. Learn your risk for He FH and get treated early to cut your chances of heart disease. He FH is caused by a change in a gene that makes it harder for your body to remove LDL cholesterol from your bloodstream. Cholesterol is a fatty, waxy substance in your blood and cells. It travels through your body in two forms: HDL and LDL. HDL helps carry cholesterol to your liver to be removed from your body. It's called "good" cholesterol. LDL is known as "bad" cholesterol because it damages arteries and can lead to heart disease. If you have He FH, you inherit a faulty gene from one of your parents. If you're a parent yourself and you have the gene, you've got a 50-50 chance of passing it to each of your children. He FH affects about 1 out of every 500 people. In white people whose families came from Europe, the rate may be as high as 1 in every 200 people. You may hear about a disease with a similar name called homozygous familial hypercholesterolemia ( Ho FH). It differs from He FH in the way it's passed down from your parents. Instead of getting a faulty gene from just one of your parents, you get Ho FH when you inherit one faulty gene from each parent. Ho FH is more severe than He FH, but it's rare. Only about 1 out of every 1 million people has it. If you don't get any treatment, He FH will cause your LDL and total cholesterol levels to go extremely high. Extra LDL cholesterol can form clumps called plaque in the walls of your arteries. The plaque narrows the arteries so less blood can flow through them. This is called hardening of the arteries. When this happens, your heart has to work harder to push blood through your body. Over time, your heart can get damaged and you can get heart disease. Narrowed blood vessels can prevent enough blood from reaching your heart. Or a piece of plaque can break off and get stuck in a blood vessel that supplies blood to your heart. If blood flow to your heart gets blocked, parts of your heart muscle can die and you'll have a heart attack. If you're a man and you don't get treatment, you can have a heart attack as early as your 40s or 50s. If you're a woman, you're also at a higher risk for a heart attack, but it can often happen later in your life, like your 60s. High cholesterol in your blood can cause other symptoms. You may have yellow or orange bumps under your skin, called xanthomas. They often form in tendons like the Achilles tendon in the back of your heel. You might also notice them in your hands, elbows, knees, and feet. When xanthomas form on the eyelids, they're called xanthelasmas. Cholesterol can also form deposits around the outside of your cornea -- the clear cover over the front of your eye. This is called corneal arcus, which looks like a silvery blue ring. You can see it as an arc that goes around the outside of your eye, but it won't affect your vision. At your visit your doctor will ask you: What symptoms do you have and when did you first notice them? Does anyone in your family have very high cholesterol? Did any of the men in your family have a heart attack in their 40s or 50s? Did any women in your family have a heart attack before age 60? If your doctor thinks you have He FH, he'll do a blood test to check your cholesterol level. With He FH, your: Total cholesterol level will be over 300 milligrams per deciliter (mg/d L) LDL cholesterol level will be over 200 mg/d L You might get another blood test to check for the gene that causes He FH. Your doctor will also do an exam to look for: Bumps in your knees, elbows, and knuckles Swelling in the back of your ankles Yellow growths on your eyelids White half-circles around the colored part of your eye Which medicines are best for me? Do the medications have side effects? What new symptoms should I watch for? How often should I see you? Do I need to see any other specialists? Which ones? Do I need to lose weight? Which foods should I avoid? How much exercise should I do and what types are best? The goal is to lower your cholesterol levels and reduce your risk for heart disease. Part of your treatment will be to make lifestyle changes, such as: Eat a low-fat diet. Avoid foods high in saturated and trans fats, like beef, pork, coconut oil, egg yolks, and whole milk. Instead, eat more veggies, fruits, whole grains, nuts, seafood, lean poultry, and low-fat dairy. Exercise. Walk, bike ride, swim, and do other activities that make your heart pump harder. Lose extra weight. If you're overweight, drop some pounds with diet and exercise. If you smoke, stop. Ask your doctor for ways to quit. Cigarettes increase your risk for heart disease. Lifestyle changes are usually not enough to treat He FH. You'll take medicine, too, to lower your cholesterol levels. Statins are the main drugs that treat He FH. They block an enzyme your body needs to make cholesterol. Some examples are: Atorvastatin ( Lipitor) Lovastatin ( Mevacor) Pravastatin ( Pravachol) Rosuvastatin ( Crestor) Simvastatin ( Zocor) Other drugs your doctor may suggest to lower cholesterol: Bile acid sequestrants (colesevelam, Welchol) Ezetimibe ( Zetia) Fibrates (fenofibrate, gemfibrozil) Nicotinic acid ( Niaspan, Slo- Niacin) PCSK9 inhibitors To protect your heart and prevent heart disease, you'll need to manage He FH throughout your life. You'll likely need to keep up a good diet, exercise, and take statins and other drugs to control your cholesterol. Tests can find out if your other family members have He FH. Close relatives like your brother, sister, or children may want to get them so they can take steps to lower their LDL cholesterol and prevent heart problems. If you plan to start a family, ask your doctor if you should have genetic testing before you get pregnant to find out if your baby could be at risk. Talk to your doctor about finding ways to meet others who have He FH. They can share with you tips for diet and exercise that have helped them. Also reach out to family and friends to get their backing and support -- especially for the diet and lifestyle changes that are an important part of He FH treatment. You can get information on resources from the FH Foundation. The organization helps people understand their diagnosis and better manage their health.