High cholesterol

What is high cholesterol?

The term high cholesterol is a bit misleading, because there are two types of cholesterol. If you've been told you have high cholesterol, it usually means you have more of the bad type and less of the good type. This may put you at higher risk of having a heart attack or a stroke.

You won't notice if you have too much bad cholesterol, because you won't have any symptoms. The only way you can find out is to have a blood test.

Key points for people with high cholesterol

• There are two main kinds of cholesterol: good cholesterol (HDL cholesterol) and bad cholesterol (LDL cholesterol).
• Eating saturated fats and trans fats can increase the amount of bad cholesterol in your blood. Saturated fats are found in foods such as meat, butter, and cream. Trans fats are found in cookies, cakes, pastries, and fast food.
• Too much bad cholesterol won't cause any symptoms, but it can increase your risk of having a heart attack or a stroke.
• You can lower your bad cholesterol by changing what you eat, taking medicines, or both. This will lower your risk of having a heart attack or a stroke.
• If you smoke, stopping smoking can increase the amount of good cholesterol in your blood, which can lower your risk of having a heart attack or a stroke.

What is cholesterol?

Cholesterol is a fatty substance that is found in every cell in your body. Only a small amount of the cholesterol in your body comes directly from food. Most is made in your liver from saturated fats that you eat.

We've all started to think that fats are bad for us, but the body needs some fats to work properly. For example, fats are a source of energy and some vitamins.

Types of fat

There are several different types of fat in the food we eat.

Saturated fats are found in meat, butter, and other dairy products. Your liver turns saturated fats into cholesterol. So if you want to lower your cholesterol level, you need to eat less saturated fat.

Unsaturated fats are divided into polyunsaturated and monounsaturated. fats. They are found in vegetable oil and olive oil.

Omega-3 fatty acids are a type of polyunsaturated fat. They are found mainly in oily fish such as mackerel, salmon, sardines, and herring, and fresh (but not canned) tuna. They can help make the blood less sticky and reduce the chances of a clot forming. So they may protect you against a heart attack. Other "good" unsaturated fats are found in leafy green vegetables, vegetable oils, and margarine.

Trans fats are solid fats found in cookies, cakes, pastries, and fast food. Scientists think that your body handles these fats in the same way as saturated fats. So if you want to lower your cholesterol, you need to eat fewer trans fats.

You don't need to know what these names mean. All you need to remember is that saturated fats and trans fats may be harmful. Eating these tends to increase the amount of bad cholesterol in your blood.

Fats in the blood are called lipids. Cholesterol is a lipid. All the fats you eat are changed into a type of cholesterol or another group of lipids called triglycerides.

How cholesterol is carried around the body

Cholesterol can't travel around the body by itself. It has to link up with other substances in the body called proteins to form particles called lipoproteins. There are several different types of lipoproteins in your blood. The two most important are called LDL and HDL.

• Low-density lipoprotein (LDL): This moves cholesterol from your liver and through your blood to your body's cells. LDL cholesterol is called bad cholesterol. This is because it can build up in your blood vessels and this increases your risk of getting heart disease. The more LDL cholesterol there is in your blood, the greater your risk of getting heart disease. When doctors say you have high cholesterol, they mean you have a lot of bad (LDL) cholesterol in your blood.
• High-density lipoprotein (HDL): This picks up any extra cholesterol from your body and takes it back to your liver. Because it clears cholesterol from your blood, it's often called good cholesterol. The more good (HDL) cholesterol you have in your blood, the lower your risk of heart disease.

What happens if cholesterol is high?

The blood flow becomes blocked as plaques build up in blood vessels.

If you have high cholesterol, it means that the level of cholesterol in your blood is outside of the normal range. For example, you may have too much bad (LDL) cholesterol and not enough good (HDL) cholesterol.

If you have too much bad cholesterol in your blood, it builds up to form fatty deposits or plaques along the inside of the blood vessels. These plaques clog up the blood vessels, making them narrower. This condition is called atherosclerosis. It is harder for blood to flow through narrowed blood vessels and this puts you at increased risk of heart disease.

Sometimes the plaques make the walls of the blood vessels bumpy. This can lead to blood clots forming inside them. When a blood clot forms on a plaque, it can block the flow of blood to your heart or brain and this can cause a heart attack or a stroke.

What types of fats do I need to watch out for?

The types of fats that you have to worry about the most are saturated fats and trans fats. These are the solid fats found in meat and meat products (such as hotdogs and hamburgers), and in dairy products (such as butter, hard cheese, milk, and cream). If you eat too much of this type of fat, the amount of bad (or LDL) cholesterol in your blood rises.

High cholesterol: why me?

Some people are more likely to get high cholesterol than others. The things that raise your chances of getting a condition are called risk factors. You can control some of the risk factors for high cholesterol, such as your diet, but you can't control others, such as your family history.

These are some of the things that can affect your cholesterol level.

• What you eat: Eating a lot of saturated fats and trans fats is likely to increase the amount of cholesterol in your blood. ² Researchers aren't sure how this happens. ¹ Trans fats are found in hard margarine and have the same effect on your body as saturated fats.
• Your genes: Some people seem to be able to eat lots of fatty food without getting abnormal levels of lipids in their blood. But other people have to be very careful about what they eat. This difference may be caused by differences in their genes (the basic material in all cells that controls how cells grow and behave). Differences in genes may affect how much cholesterol your body makes and how it handles the fat in the food you eat.
• Lack of exercise: Not getting regular exercise can increase triglycerides and reduce good cholesterol.
• Being overweight: Putting on weight can have the same effect on cholesterol as not exercising.
• Getting older: Cholesterol tends to rise as we get older.
• Drinking alcohol to excess: Drinking a lot of alcohol on a regular basis can increase your cholesterol and triglycerides.
• Severe lipid disorders: Some lipid disorders are inherited, which means that faulty genes are passed on from one or both parents. People with one of these disorders have high levels of lipids and are more likely to have heart or circulation problems, even when they are quite young. These types of lipid disorders are rare.

Other risk factors for heart disease

When doctors talk about risk factors for heart disease, they are talking about the things that raise your chances of having a heart attack or a stroke. Having a high level of bad cholesterol is not the only risk factor for heart disease. Other things count, too, especially your age, your blood pressure, whether or not you have diabetes, and whether or not you smoke. Your doctor will consider these before deciding whether you should have a cholesterol test to see whether you need treatment.

For example, if your level of bad (LDL) cholesterol is slightly high, but you have no other risk factors for heart disease, your doctor will probably not worry too much. He or she may give you some advice about what you eat and check your cholesterol again after a few months. But you probably won't need drug treatment.

On the other hand, if you have low levels of good (HDL) cholesterol and high levels of bad (LDL) cholesterol, as well as high blood pressure and diabetes, then your doctor may consider drug treatment.

Many people who have too much bad cholesterol in their blood also have too much triglyceride in their blood. Triglycerides are another type of fat in the blood. High levels of triglycerides can be harmful. But it's not clear how triglycerides might cause heart disease.

Most doctors now agree that there is more and more evidence that having a lot of triglycerides in the blood raises your chance of getting narrowing of the arteries (atherosclerosis) and heart disease.

lung cancer

What is lung cancer?

It can be devastating to find out that you or someone close to you has lung cancer. It's a serious illness in which some of the cells in your lungs have started to grow out of control, invading and destroying other cells. In the weeks and months to follow, you will probably have many different emotions, including anxiety about what lies ahead.

Almost before you have had time to take in what the doctors have told you, you will be offered a range of tests and treatments that aim to get rid of your cancer or relieve your symptoms, or both. The treatments you're offered will depend on the type of lung cancer you have, how large it is, and whether it has spread. A lot will also depend on how you feel about your illness and how you would like it to be treated.

If you are diagnosed with lung cancer, you will need to make some important decisions about your treatment.

We hope our information will answer your questions about lung cancer. It may also help you to talk with your doctor about the best treatments for you.

Some people want to know more about their cancer than others. Some will choose to have treatments that may help them live longer but which could have unpleasant, sometimes harmful, side effects. Other people prefer to enjoy as much of life as they can. 

There's no right or wrong way for you to deal with your cancer. The most important thing is for you to feel comfortable with the decisions you make. It's also essential that your medical team and those who care about you listen to what you say and respect your wishes.

Key points for people with lung cancer

• Lung cancer is the second most common type of cancer in both men and women (not counting skin cancer). It is the leading cause of death from cancer in the United States.
• By the time they are diagnosed, most people's lung cancer has spread outside of their lungs.
• You will be offered a range of treatments that aim to get rid of the cancer and improve your symptoms.
• Most treatments have side effects. These should be weighed against the benefits of the treatment.
• Cigarette smoking is the most common cause of lung cancer. The best way to prevent lung cancer is not to smoke.

Your lungs and what they do

You have two lungs. They sit in your chest, inside your rib cage, one on each side of your heart. They are covered by a layer of moist tissue called the pleura.

When you breathe in, your lungs fill with air.

Your lungs are a little like two spongy, elastic bags that fill up with air as you breathe in. They empty as you breathe out. The right lung is divided into three sections. These sections are called lobes. The left lung has two sections (or lobes).

Keeping your lungs healthy is important. They take oxygen from the air you breathe, which your blood then carries around your body. When you breathe out, they get rid of carbon dioxide, which is a waste product made by your body.

Here's how air travels into your lungs.

Your windpipe (trachea) is the air passage that leads from your throat into your chest. In your chest, your windpipe divides into two smaller airways (called bronchi). Each airway leads into a lung.

Inside your lungs, the airways divide into even smaller airways (called bronchioles). At the end of each of these smaller airways are little air sacs (called alveoli).

When you breathe in, air travels down your windpipe, through the airways, into your lungs and then into the smaller airways and the air sacs.

The air sacs in your lungs are connected to the network of blood vessels that surrounds your lungs. Oxygen from the air you breathe in passes through the thin walls of the air sacs and into these blood vessels. Then, the oxygen is carried back to your heart and pumped around your body. At the same time, carbon dioxide (which is made as a by-product of breathing) passes from your blood into the air sacs. The carbon dioxide leaves your body when you breathe out.

This is an X-ray picture of normal lungs. You can see the heart in the middle.

Also inside your chest, lying between your lungs, are:

• Your heart
• The main blood vessels that carry blood to and from your heart and the rest of your body
• The tube that carries food from your mouth to your stomach. This tube is called the esophagus.

What goes wrong in lung cancer?

When your body's cells are healthy, they divide, grow old, then die and are replaced in an orderly way. But when you get cancer, your cells grow and multiply too quickly.

In lung cancer, abnormal cells group together to form a lump called a tumor.

This means your cells don't have time to develop into normal, healthy cells. They may be the wrong shape and may not work properly. And they tend to lie on top of one another instead of in neat rows. Lung cancer can start almost anywhere in your lungs, but it usually starts in your airways. Abnormal cells tend to group together and form a lump, which is called a tumor. This slowly gets bigger.

Nearly all types of lung cancer can spread to other parts of your body and form more tumors. These are called secondary tumors. You may hear doctors talk about metastasis. This is the word doctors use to describe the way cancer spreads.

Types of lung cancer

Doctors divide lung cancer into two main kinds, based on what the cancer cells look like when examined in the laboratory.

The main types of lung cancer are:

Non-small-cell lung cancer (NSCLC). This is the most common kind. About 4 in 5 cases of lung cancer are this type. It can start in different parts of the lung. There are three different types of non-small-cell cancer.

• Adenocarcinoma: This kind of cancer grows in certain glands that produce mucus. It usually starts in the airways at the outer edges of the lungs. It is the most common type of non-small-cell lung cancer, making up about two-fifths of all cases of lung cancer.
• Squamous cell carcinoma: This is a slow-growing cancer that affects the airways. It makes up about one-third of all lung cancers.
• Large cell carcinoma: This type of cancer is made up of larger cells than other forms of lung cancer. About 15 percent of lung cancers are this type. ³

Small-cell lung cancer (SCLC). About 1 in 5 cases of lung cancer are this type. Doctors also call this sort of lung cancer oat cell cancer because it's made up of small cells that look like oats. These cells grow and spread more quickly than the cells in non-small-cell lung cancer.

Lung cancer: why me?

Some things increase your chance of getting lung cancer. Doctors call these things risk factors. Having a risk factor doesn't mean you'll definitely get lung cancer. It just means you're more likely to get it than someone who doesn't have the risk factor.

We've listed the main risk factors for lung cancer below. The most important is smoking. But sometimes people who have never smoked still get lung cancer.

If you think you have a high risk of getting lung cancer, you may wonder if there is some way of being tested that would catch lung cancer early, before it grows. This kind of test is called screening, but so far it hasn't been very successful for finding lung cancer.

Smoking

Smoking is responsible for 8 out of 10 deaths from lung cancer. Men who smoke are 22 times more likely to die from the disease than those who don't smoke. Women who smoke have a 12-fold greater risk of dying from lung cancer than nonsmokers.

Smoking leads to cancer because cells in the lung become damaged by poisonous chemicals in cigarette smoke. And, over time, these cells become cancerous.

How much you smoke is important, too. If you smoke less than half a pack per day, you're 15 times more likely to die from lung cancer than a nonsmoker. If you smoke one or two packs daily, you're 42 times more likely to die from lung cancer than someone who doesn't smoke.

Switching to a different brand with less tar or less nicotine does not make any difference to your risk of getting lung cancer. There's no such thing as a safer cigarette. The poisonous chemicals in smoke that can cause lung cancer are also found in marijuana cigarettes, so these are not a safe option.

Smoking cigars or a pipe also gives you a higher chance of getting lung cancer, even if you don't inhale.

Living or working in a smoky atmosphere makes it more likely you will get lung cancer, even if you don't smoke. This is called passive smoking. Living with a smoker increases your risk of lung cancer by one-third. ⁵ In 1990, the Environmental Protection Agency estimated that between 3,000 and 4,000 deaths from lung cancer were caused by passive smoking.

If you smoke or used to smoke, you may feel that this has caused your lung cancer and you may feel guilty. You may think other people blame you for getting lung cancer. You may even think that your doctor doesn't have much sympathy. But you shouldn't blame yourself for smoking. Nicotine is a highly addictive drug. And most people start smoking when they are teenagers and get addicted when they're too young to know any better. Also, some people with lung cancer have never smoked at all.

Being of a certain ethnic group

If you're African-American, you have a higher chance of getting lung cancer than a white American. Researchers think that this is because more African-Americans smoke, although there may also be a difference in the way their bodies deal with tobacco smoke. Researchers also think that African-Americans may, on average, have more fat in their diet. This could have an effect on their risk of getting lung cancer. ⁷ If you're African-American or native Hawaiian and smoke less than 30 cigarettes a day, you are more likely to get lung cancer than other groups of Americans who also smoke the same amount.

People who are Native American, Hispanic, Asian-American, or Japanese-American all have less lung cancer than average in the United States. These groups tend to smoke less, and the lower levels of lung cancer may also be linked to differences in diet and their genes (the inherited material in cells that controls how cells behave and grow). These tables show how common cancer is in different ethnic groups in the United States.

Men

Ethnic group	Number of lung cancer cases per 100,000 men
Native American	14
Hispanics, Japanese, Chinese, Filipinos, Koreans	42 to 53
Alaska Natives, Hawaiians, whites, Vietnamese	71 to 89
African-Americans	117

Women

Ethnic group	Number of lung cancer cases per 100,000 women
Japanese	15
Koreans, Filipinos, Hispanics, Chinese	16 to 25
African-Americans, Vietnamese, whites, Hawaiians	31 to 44
Alaska Natives	51

Being older

Lung cancer is more common in older people, probably because they have been smoking longer. In the United States, only around 2 in 100 people who have lung cancer are under age 45 when they get the disease.

Young people who get lung cancer tend to be heavy smokers who started smoking at a young age. They also tend to have a family history of the disease. ⁷

Working in certain industries

If you work with certain materials used in industry, you may have a higher chance of getting lung cancer. About 10 percent to 15 percent of lung cancer cases are probably due to working with cancer-causing substances, the most common of which is asbestos. 

All types of asbestos fibers cause lung cancer, but long-term exposure to types of asbestos called crocidolite or amosite carries the highest risk. It can take many years for the cancer to develop. The dangers of asbestos are now well-known, and there are laws governing how it is used. So there should be fewer lung cancers due to asbestos in the future.

Other chemicals that can cause lung cancer include arsenic and chromium. Nickel and vinyl chloride also carry a small risk. These substances are used in various industries, but there are laws about their use.

Living with radon

Radon is an invisible, odorless, and tasteless gas that is found naturally in soil and rocks. High levels of radon are found in buildings built on land that contains a lot of radon. If you live or work in one of these areas, you may have an increased chance of getting lung cancer.

The average concentration of radon in the home is 1.25 pCi/L, where pCi/L stands for picocuries (a measure of the amount of radon) per liter of air. Radon levels more than 4 pCi/L are considered unsafe. Although radon gas is thought to cause lung cancer, researchers haven't proved whether there is a link. 

Living with air pollution

Some studies have suggested there might be a link between air pollution and lung cancer. Researchers are trying to find out why this might be. If you breathe in certain particles from the air, they may damage the cells in your lungs. These damaged cells may become cancerous.

The main air pollutants are from motor vehicles, and include carbon monoxide, hydrocarbons, sulfur oxide, and nitrogen oxide. However, if pollution does cause cancer, the risk is tiny compared to the risk from smoking. Studies have shown that air pollution may cause less than 1 in 100 cases of lung cancer. 

Having other lung diseases

If you have one or more other persistent (chronic) lung diseases, such as tuberculosis, asthma, emphysema, or chronic bronchitis, you are slightly more likely to get lung cancer than other people.

If you smoke, you may have a condition called chronic obstructive pulmonary disease (COPD). If you have COPD, you are more likely to get lung cancer. ⁷ In COPD, not enough air flows into or out of the lungs. COPD is nearly always caused by smoking.

Having lung cancer in your family

If your parents, brothers, or sisters have had lung cancer, you are slightly more likely to get the disease than people with no family history. 

What stage is your lung cancer?

The TNM system is used to classify your lung cancer. It looks at three factors:

• T is for tumor
• N is for (lymph) nodes
• M is for metastasis. (Metastasis is when the cancer spreads to other parts of your body, such as your bones.)

Each factor is given a number. Generally, lower numbers mean your cancer is smaller and has not spread far (if at all).

• For T: The number tells you how big your cancer is and whether the cancer has spread outside the lung.
• For N: The number tells you whether your lung cancer has spread to your lymph nodes. Cancer cells can grow in the nodes and then travel from there to other parts of the body.
• For M: The number tells you whether your lung cancer has spread to other parts of your body.

The numbers are then sometimes followed by letters. These tell the doctor how the cancer was found and they give more detail about how far it has spread.

Here is an explanation of what each letter and number says about your cancer.

TNM		What it means
T (tumor)	TX	Cancer cells have been found but your doctor cannot find a tumor (lump).
	T0	There is no sign of lung cancer.
	Tis	Your tumor is only in the lining of the airway (in the bronchus or bronchiole). Doctors call this carcinoma in situ.
	T1	The size of your tumor is 3 centimeters (cm) or less.
	T2	Your tumor is more than 3 cm in size and it has started to grow into the covering around your lungs (pleura). But it is at least 2 cm from the point at which your windpipe (trachea) divides into the left and right airways (bronchi).
	T3	Your tumor has spread into the covering around the lungs (pleura) or chest wall and is less than 2 cm from the point at which the windpipe (trachea) divides into the left and right airways (bronchi).
	T4	Your tumor has spread to other tissues in your chest, such as your heart, your main blood vessels, your windpipe (trachea) or the tube that carries food to the stomach (esophagus). Or it is growing on the covering around the lung (pleura). This causes fluid containing cancer cells to build up around the lung.
N (nodes)	NX	Doctors can't tell if there's cancer in your lymph nodes. (You may not have been able to undergo the necessary tests.)
	N0	Your lung cancer has not spread to your lymph nodes.
	N1	Your lung cancer has spread to lymph nodes near your lung.
	N2	Your lung cancer has spread to lymph nodes in the middle of your chest.
	N3	Your lung cancer has spread to lymph nodes near your other lung or to lymph nodes above your collarbone.
M (metastasis)	MX	Doctors can't tell if your cancer has spread. (You may not have been able to undergo the necessary tests.)
	M0	Your lung cancer has not spread to another part of your body.
	M1	Your lung cancer has spread to another lobe of your lung or to another part of your body.

Key:

2 cm = 8/10 of an inch

3 cm = 1.2 inches

If your lung cancer is described as T1N1M0, it means that the tumor (lump) is 3 centimeters or smaller in size, has spread only to lymph nodes nearby and has not spread to other parts of your body.

Staging non-small-cell lung cancer

If you have non-small-cell lung cancer, doctors use the TNM system to stage your cancer on a scale of 0 through 4. Stage 0 is the least advanced stage of lung cancer (doctors call it carcinoma in situ) and stage 4 is the most advanced. Doctors call stage 1 and stage 2 lung cancer early disease. Stage 3A is called locally advanced disease, and stages 3B and 4 are advanced disease. Most people with lung cancer have advanced disease by the time they are diagnosed.

Here is an explanation of what stages 1 to 4 mean.

• Stage 1: The cancer is only in the lung.
• Stage 2: The cancer is small but has spread to the lymph nodes closest to the affected lung (stage 2A) or into the chest wall, the outer covering of the lung, the diaphragm or the outer covering of the heart (stage 2B).
• Stage 3: The cancer has spread to the lymph nodes further away from the affected lung but is still on the same side of the chest (stage 3A) or to the lymph nodes on the other side of the chest or collar bone, or to other places in the chest (stage 3B). Stage 3B can also mean that there is more than one tumor in the lung or that fluid around the lung (also known as pleural fluid) contains cancer cells.
• Stage 4: The cancer has spread to another lobe of the lung from where it started, or to other parts of the body (for example, the liver, or brain).

By the time they are diagnosed:

• A quarter of non-small-cell lung cancer patients have cancer that hasn't spread
• A fifth have cancer that has spread to nearby lymph nodes
• More than half have cancer that has spread to other distant parts of the body.

Staging small-cell lung cancer

If you have small-cell lung cancer, your doctors won't describe the stage in such a complicated way as for non-small-cell lung cancer. ¹⁶ They will describe the cancer as one of two types.

• Limited stage disease: The cancer is on one side of the chest
• Extensive stage disease: The cancer has spread beyond one side of the chest.

About two-thirds of people with small-cell lung cancer have extensive disease when they are diagnosed, and about one-third have limited stage disease.