Cholesterol is a waxy, fat-like substance that's found in all the cells in the body. The liver makes cholesterol, and it is also in some foods, such as meat and dairy products. The body needs some cholesterol to work properly. But if your child or teen has high cholesterol (too much cholesterol in the blood), it can stick to the walls of their arteries and narrow or even block the arteries. This can put your child or teen at risk of coronary artery disease and other heart diseases.

Three main factors contribute to high cholesterol in children and teens:

• An unhealthy diet, especially one that is high in saturated fats
• A family history of high cholesterol, especially when one or both parents have high cholesterol
• Having obesity

Some diseases, such as diabetes, kidney disease, and certain thyroid diseases, can also cause high cholesterol in children and teens.

There are usually no signs or symptoms that your child or teen has high cholesterol.

There is a blood test to measure cholesterol levels. The test gives information about:

• Total cholesterol. This is a measure of the total amount of cholesterol in your blood. It includes both low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol.
• LDL cholesterol. LDL is often called "bad" cholesterol because it is the main source of cholesterol buildup and blockage in the arteries.
• HDL cholesterol. HDL is often called "good" cholesterol because it helps remove cholesterol from your arteries.
• Non-HDL. This number is your total cholesterol minus your HDL. Your non-HDL includes LDL and other types of cholesterol such as VLDL (very-low-density lipoprotein).
• Triglycerides. This is another type of fat in your blood that can raise the risk of heart disease.

For anyone aged 19 or younger, the healthy levels of cholesterol are

When and how often your child or teen should get this test depends on their age, risk factors, and family history. The general recommendations are:

• The first test should be between ages 9 to 11
• Children should have the test again every 5 years
• Some children may have this test starting at age 2 if there is a family history of high cholesterol, heart attack, or stroke

Lifestyle changes are the main treatment for high cholesterol in children and teens. These changes include:

• Being more active. This includes getting regular physical activity and spending less time sitting (in front of a television, at a computer, on a phone or tablet, etc.).
• Healthy eating. A diet to lower cholesterol includes limiting foods that are high in saturated fat, sugar, and cholesterol. It is also important to eat plenty of fresh fruits, vegetables, and whole grains.
• Losing weight, if your child or teen is overweight or has obesity.

If everyone in the family makes these changes, it will be easier for your child or teen to stick to them. It is also an opportunity to improve your health, and the health of the rest of your family.

Sometimes these lifestyle changes are not enough to lower your child or teen's cholesterol. Their health care provider may consider giving your child or teen cholesterol medicines if they:

• Are at least 10 years old.
• Have an LDL (bad) cholesterol level that is higher than 190 mg/dL, even after six months of diet and exercise changes.
• Have an LDL (bad) cholesterol level that is higher than 160 mg/dL AND are at high risk for heart disease.
• Have familial hypercholesterolemia (FH). FH is an inherited disorder that causes very high levels of cholesterol in the blood.

Having HIV/AIDS weakens your body's immune system. It destroys the white blood cells that fight infection. This puts you at risk for opportunistic infections (OIs). OIs are serious infections that take advantage of your weak immune system. These infections are less common and less severe in healthy people.

There are many types of OIs:

• Bacterial infections, including tuberculosis and a serious related disease, Mycobacterium avium complex (MAC)
• Viral infections, such as cytomegalovirus (CMV) and hepatitis C
• Fungal infections, like yeast infections, cryptococcal meningitis, pneumocystis carinii pneumonia (PCP) and histoplasmosis
• Parasitic infections, such as crypto (cryptosporidiosis) and toxo (toxoplasmosis)

Having HIV/AIDS can make infections harder to treat. People with HIV/AIDS are also more likely to have complications from common illnesses such as the flu.

You can help prevent infections by taking your HIV/AIDS medicines. Other things that can help include practicing safe sex, washing your hands well and often, and cooking your food thoroughly.

HIV stands for human immunodeficiency virus. It harms your immune system by destroying CD4 cells. These are a type of white blood cells that fight infection. The loss of these cells makes it hard for your body to fight off infections and certain HIV-related cancers.

Without treatment, HIV can gradually destroy the immune system and advance to AIDS. AIDS stands for acquired immunodeficiency syndrome. It is the final stage of infection with HIV. Not everyone with HIV develops AIDS.

The treatment of HIV with medicines is called antiretroviral therapy (ART). It involves taking a combination of medicines every day. ART is recommended for everyone who has HIV. The medicines do not cure HIV infection, but help people with HIV live longer, healthier lives. They also reduce the risk of spreading the virus to others.

HIV medicines reduce the amount of HIV (viral load) in your body, which helps by:

• Giving your immune system a chance to recover. Even though there is still some HIV in your body, your immune system should be strong enough to fight off infections and certain HIV-related cancers.
• Reducing the risk that you will spread HIV to others.

There are many different types (called classes) of HIV medicines. Some work by blocking or changing enzymes that HIV needs to make copies of itself. This prevents HIV from copying itself, which reduces the amount of HIV in the body. Several types of medicines do this:

• Nucleoside reverse transcriptase inhibitors (NRTIs) block an enzyme called reverse transcriptase
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs) bind to and later change reverse transcriptase
• Integrase inhibitors, also called integrase strand transfer inhibitors (INSTIs), block an enzyme called integrase
• Protease inhibitors (PIs) block an enzyme called protease

Some types of HIV medicines interfere with HIV's ability to infect CD4 immune system cells:

• Fusion inhibitors block HIV from entering the cells
• CCR5 antagonists and post-attachment inhibitors block different molecules on the CD4 cells. To infect a cell, HIV has to bind to two types of molecules on the cell's surface. Blocking either of these molecules prevents HIV from entering the cells.
• Attachment inhibitors bind to a specific protein on the outer surface of HIV. This prevents HIV from entering the cell.

Pharmacokinetic enhancers are another type of medicine. They are sometimes taken along with certain other HIV medicines. Pharmacokinetic enhancers increase the effectiveness of the other medicine. They work by slowing the breakdown of the other medicine. This allows that medicine to stay in the body longer at a higher concentration.

There are also multidrug combinations, which include a combination of two or more different types of HIV medicines.

It's important to start taking HIV medicines as soon as possible after your diagnosis, especially if you:

• Are pregnant
• Have AIDS
• Have certain HIV-related illnesses and infections
• Have an early HIV infection (the first 6 months after infection with HIV)

You and your health care provider will work together to come up with a personal treatment plan. This plan will be based on many factors, including:

• The possible side effects of HIV medicines
• Potential drug interactions with any other medicines you take
• How many medicines you will need to take every day
• Any other health problems you may have

It's important to take your medicines every day, according to the instructions from your provider. If you miss doses or don't follow a regular schedule, your treatment may not work, and the HIV virus may become resistant to the medicines.

HIV medicines can cause side effects. Most of these side effects are manageable, but a few can be serious. Tell your provider about any side effects that you are having. Don't stop taking your medicine without first talking to your provider. There may be steps you can take to help manage the side effects. In some cases, your provider may decide to change your medicines.

HIV medicines are not just used for treatment. Some people take them to prevent HIV. PrEP (pre-exposure prophylaxis) is for people who don't already have HIV but are at very high risk of getting it. PEP (post-exposure prophylaxis) is for people who have possibly been exposed to HIV.

NIH: Office of AIDS Research

Hormones are your body's chemical messengers. They travel in your bloodstream to tissues or organs. They work slowly, over time, and affect many different processes, including:

• Growth and development
• Metabolism - how your body gets energy from the foods you eat
• Sexual function
• Reproduction
• Mood

Endocrine glands, which are special groups of cells, make hormones. The major endocrine glands are the pituitary, pineal, thymus, thyroid, adrenal glands, and pancreas. In addition, men produce hormones in their testes and women produce them in their ovaries.

Hormones are powerful. It takes only a tiny amount to cause big changes in cells or even your whole body. That is why too much or too little of a certain hormone can be serious. Laboratory tests can measure the hormone levels in your blood, urine, or saliva. Your health care provider may perform these tests if you have symptoms of a hormone disorder. Home pregnancy tests are similar - they test for pregnancy hormones in your urine.

Around half of American adults have high blood pressure (hypertension). Many of those people don't know they have it because there are usually no warning signs. This can be dangerous, because high blood pressure can lead to life-threatening conditions like heart attack or stroke. The good news is that you can often prevent or treat high blood pressure. Early diagnosis and heart-healthy lifestyle changes can keep high blood pressure from seriously damaging your health.

Each time your heart beats, it pumps blood into your arteries (the blood vessels that carry blood from your heart to the tissues and organs in your body). Blood pressure is the force of your blood pushing against the walls of your arteries. Blood pressure is measured as two numbers:

• Systolic pressure (the first and higher number) measures pressure inside your arteries when your heart beats
• Diastolic pressure (the second and lower number) measures the pressure inside your arteries when your heart rests between beats

As an example, a blood pressure reading of 120/80 means a systolic of 120 and a diastolic of 80.

High blood pressure usually has no symptoms. So the only way to find out if you have it is to get regular blood pressure checks from your health care provider. Your provider will use a gauge, a stethoscope or electronic sensor, and a blood pressure cuff. They will take two or more readings at separate appointments before making a diagnosis:

For children and teens, the provider compares the blood pressure reading to what is normal for other kids who are the same age, height, and sex.

Anyone can develop high blood pressure, but there are certain factors that can increase your risk:

• Age. Blood pressure tends to rise with age.
• Race/Ethnicity. High blood pressure is more common in Black adults. They also tend to have higher average blood pressure numbers and get high blood pressure earlier in life.
• Sex. Men are more likely than women to develop high blood pressure throughout middle age. But in older adults, women are more likely than men to develop high blood pressure.
• Lifestyle. Certain lifestyle habits can raise your risk for high blood pressure, such as eating too much sodium (salt) or not enough potassium, lack of exercise, drinking too much alcohol, and smoking.
• Family history and genetics. High blood pressure often runs in families. Many genes are linked to small increases in high blood pressure risk.
• Social and economic factors:
  • Research shows that factors such as income, education level, where you live, and the type of job you have may raise your risk of high blood pressure. For example, working early or late shifts can raise your risk.
  • Experiencing discrimination and poverty has been linked to high blood pressure. Also, some research has shown that trauma in childhood may raise the risk of high blood pressure.
• Certain medicines. Some medicines can raise your blood pressure, including:
  • Certain antidepressants
  • Decongestants (medicines to relieve a stuffy nose)
  • Hormonal birth control pills
  • Non-steroidal anti-inflammatory drugs (NSAIDs), which are a type of pain reliever
• Having certain other medical conditions, such as:
  • Some tumors
  • Chronic kidney disease
  • Diabetes
  • Metabolic syndrome
  • Overweight and obesity
  • Sleep apnea
  • Thyroid problems

You can help prevent high blood pressure by having a healthy lifestyle. This means:

• Eating a healthy diet. To help manage your blood pressure, you should limit the amount of sodium (salt) that you eat and increase the amount of potassium in your diet. It is also important to eat foods that are lower in fat, as well as plenty of fruits, vegetables, and whole grains. The DASH eating plan is an example of an eating plan that can help you to lower your blood pressure.
• Getting regular physical activity. Regular physical activity can help you maintain a healthy weight and lower your blood pressure.
• Being at a healthy weight. Being overweight or having obesity increases your risk for high blood pressure. Maintaining a healthy weight can help you control high blood pressure and reduce your risk for other health problems.
• Limiting alcohol. Drinking too much alcohol can raise your blood pressure. It also adds extra calories, which may cause weight gain.
• Not smoking. Cigarette smoking raises your blood pressure and puts you at higher risk for heart attack and stroke. If you do not smoke, don't start. If you do smoke, talk to yourprovider for help in finding the best way for you to quit.
• Managing stress. Learning how to relax and manage stress can improve your emotional and physical health and lower high blood pressure. Stress management techniques include exercising, listening to music, focusing on something calm or peaceful, and meditating.
• Getting enough high-quality sleep.

If you already have high blood pressure, it is important to prevent it from getting worse or causing complications. You need to get regular medical care and follow your treatment plan. Your plan will include healthy lifestyle habit recommendations and possibly medicines.

NIH: National Heart, Lung, and Blood Institute