Asthma is an illness that narrows the breathing passages. As a result, not enough air can enter and leave your lungs. According to the World Health Organisation over 230 million people around the world are suffering from asthma. Among children it is the most chronic disease. While asthma occurs in almost all countries, asthma-related deaths happen mainly in the poorer countries of the Third World.

In America over 25 million people and 7 million children develop asthma every year. The disease is more common among African Americans. The death rate among this group is five times as high as among whites. The WHO warns that asthma rates are increasing by 50 % every ten years. Asthma also causes a loss of business and does damage to the economy because many people stay at home when they are ill.

Asthma deaths per million people (2012)
Image: Chris55, CC BY-SA 4.0, via Wikimedia Commons
Data from : World Health Organisation

Asthma occurs when tissue in your throat begins to expand or swell. Muscles in these passages become tighter and cells begin to produce some sticky substance, which makes airways even smaller. This makes it difficult for air to flow into your lungs. When this happens we call it an asthma attack. Victims fight to get enough air into their lungs, sometimes they have to cough and they breathe heavily. Sometimes asthma victims have a pain in the chest. Such an illness can deeply influence a person’s health and may even lead to death.

Doctors are not sure what causes asthma. Some argue that environmental influences are the main factors; however, some doctors claim that genes are also responsible for asthma. Almost half of the parents who suffer from asthma will also pass it on to their children. 70% of all people who have asthma also suffer from allergies, when the body reacts in an unusual way towards mostly harmless substances.

Many things can trigger asthma attacks, sometimes pollen that fly through the air, at other times dust, animal hair, mold or dampness. Air pollution from motor vehicles, factories, smoking, household sprays and other chemicals can lead to asthma. Exercising in cold weather can also trigger an asthma attack.

Many doctors prescribe asthma patients albuterol. Asthma victims often use a machine that turns this medicine into a fog-like spray that is connected to a mask that fits over your nose and mouth. It helps reduce the swelling of the airways.There are some things that individuals can do to reduce the suffering caused by asthma. They should know when and how to take their medicine and how to treat asthma attacks when they occur.

There are also new methods that have been tried out. Researchers have tested a new vaccine that protects people from dust. It produces dust particles of its own and makes the human body immune to dust.

Left : Normal airways – Right : Airways during asthma attack
Image: BruceBlaus, CC BY-SA 4.0, via Wikimedia Commons

Inhaler used during an asthma attack
Image: James Heilman, MD, CC BY-SA 3.0,
via Wikimedia Commons

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Words and Definitions

The body mass index (BMI) is a formula to measure obesity. It uses a combination of height and weight. A BMI score of 25 or higher shows that you are overweight, and a BMI of over 30 indicates obesity.

Childhood Obesity
“Teen and childhood obesity” by Gaulsstin is licensed under CC BY 2.0 

Who is at risk ?

Regular exercise helps to control your weight
Image: https://pixabay.com/vectors/woman-exercising-biking-fitness-32818/

If you are gaining weight it does not always mean that you are becoming obese. Children and young adults need nutrients in order to grow, so they gain weight as time goes on. However, if you consume more than you need and begin putting on extra weight you may be on the road to obesity – combined with all kinds of health problems.

Here are some signs that tell you if you are at risk:

• Children who have obese parents or grandparents are in greater danger of becoming obese than others
• If diseases like high blood pressure, high cholesterol, type 2 diabetes or heart illnesses run in your family you might be at risk too.
• Bowed legs at an early age can be a warning signal for obesity.
• Depression and a lack of confidence have also been connected to obesity.
• People who don’t get enough exercise and sit around and do nothing all day long are definitely more at risk than others.

What causes childhood obesity?

The explanation is really simple: if you take in more energy in the form of food than you use up you will gain weight. There are, however, many factors that can influence this.

Genes determine how your body stores food and how well it turns food into energy. Our bodies are built to store energy in fat cells for times when food is scarce. But not all bodies are the same. Your genes come from your parents, so overweight parents are more likely to have overweight children.

Although you may have good genes you still can become obese. One of the main causes of obesity is the lack of physical exercise. An average child spends less time exercising than children did ten or twenty years ago. Our free time activities have changed. Instead of going outside and doing something physical children sit still for hours in front of computers, TV and video games.

Image : https://pixabay.com/illustrations/remove-overweight-children-adults-1050369/

Snacks and Fast Food

Many of us eat up to four meals a day thanks to excessive snacking. And when we have a snack we don’t eat a carrot or an apple. Instead we reach for junk food. But this is not always the children’s fault. Schools are full of vending machines that offer high calorie snacks and sugary soft drinks. To make things worse they are bombarded with TV ads and commercials for unhealthy food. An average American eight-year old watches more than four thousand food ads a year. About 35% of these ads are for candy and snacks, another 10% for fast food.

Fast food is another reason for obesity. While some fast food chains offer healthy alternatives, these aren’t what people order. Today’s families also eat out a lot more than earlier generations.

Vending machine with snacks in Hong Kong
Images : Waoceanu, CC BY-SA 3.0, via Wikimedia Commons

Eating Habits at Home

If you develop healthy eating habits, you’ll be more likely to keep a healthy weight. And it’s at home where we form such habits.

If your parents are overweight or obese chances are that you may have seen wrong eating habits your whole life. Children who observe their parents eat a cookie instead of a piece of fruit, take their meals in front of the TV set or eat too quickly are more likely to do the same. This increases their chances of becoming overweight children and, later on, adults.

What Childhood Obesity Can Lead To

Apart from the need for larger school desks and airline seats, what else is there to worry about.

• Type 2 diabetes was once thought to be a disease that mainly affected adults, but this not longer true. It can lead to blindness, heart and kidney diseases and damage your nerves.
• Studies have shown that obesity can cause children with asthma to use more medicine and wheeze more. Overweight children and adolescents are more likely to have high blood pressure than children with a normal weight.
• Sleeping disorders are among the most common consequences of childhood obesity. Some children may even have pauses in their breathing during sleep. If not treated it may lead to a series of other illnesses, including heart and lung problems.

Obesity can lead to high blood pressure
Image: https://pixabay.com/de/photos/arzt-untersuchung-blutdruck-4303020/

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Childhood obesity 10 times higher than in the 1970s
Childhood obesity

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Key

Some illnesses only occur in certain areas. If you travel, for example, to tropical regions, you should get vaccines to protect you from yellow fever, malaria or hepatitis.

Vaccines have saved the lives of millions of people in the past and virtually eradicated many diseases. Smallpox, for example, was once one of the world’s most serious diseases, which killed millions every year. By the end of the 1970s smallpox had disappeared completely because nearly everyone was vaccinated.

The first vaccines were created towards the end of the 18th century. An English scientist, Edward Jenner, carried out experiments with cowpox, a milder form of smallpox. He found out that people who got cowpox rarely got ill from smallpox. In France, Louis Pasteur developed a weak form of rabies to protect people from dog bites. In the 20th century polio has been wiped out completely.

Today there are vaccines for many illnesses. The most common are the flu, cholera, the plague , hepatitis. Although vaccination is widely available and a part of the regular health program in almost all industrial countries, there are still countries, especially in the Third World where people die of serious diseases. Each year about three million children are killed by diseases that could have been prevented. In developing countries almost two thirds of all children are not vaccinated. The World Health Organization is fighting to provide vaccines for these children.

In March 2020, the World Health organization declared the outbreak of the COVID-19 pandemic. While a typical vaccine takes years to develop , the pharmaceutical industry an effective vaccine in only 8 months. By the middle of 2021 over 80% of the population of higher and middle income countries had been vaccinated. In the meantime there are several vaccines and drugs that have been developed for the COVID-19 disease.

COVID-19 vaccine
Image : Spencerbdavis, CC BY 4.0, via Wikimedia Commons

Exercises

Cancer is a dangerous disease in which certain cells in our body grow in an uncontrolled way. It is one of the world’s most serious illnesses. Together with heart attacks, it kills more people than any other disease in the world.

The human body has billions of cells. They are tiny elements of living material. Cells always reproduce themselves. Normally our body controls this process. It tells cells to divide themselves when we need it and to stop when we don’t. Sometimes, however, cell growth gets out of control and the production of cells doesn’t stop.

These cells that produce new tissue are called tumours. They can be benign (good) tumours or malignant(bad) tumours. A benign tumour usually stays in the same area in which it starts growing. It is often harmless. A malignant tumour however is dangerous. It can grow and spread to healthy cells and destroy them. Cells from malignant tumours can also spread to other parts of the body and produce more tumours. These malignant tumours are the ones that cause cancer and may even lead to death. Sometimes they enter the blood and lymphatic system. When this happens, cancer metasizes.

Our body’s lymphatic system

Image: (modified version) File: Illu lymphatic system.jpg, CC BY 3.0,
via Wikimedia Commons

Types of Cancer

There are over a hundred different types of cancer. Although it can strike people of all ages, older people get cancer more often than younger ones. Cancer is not one single illness. It can attack all parts of the body and spread to other areas.

Among the most common types of cancer are:

• Bone cancer – most cases are caused by cancer somewhere else in the body
• Brain tumours – there are several different types, depending on the cells of your brain
• Breast cancer – the most common form of cancer in women around the world
• Bowel cancer – this form of cancer can be best treated if you detect it early
• Leukemia – blood cancer affects people of all ages groups
• Lung cancer – is one of the deadliest forms of cancer
• Prostate cancer – one of the most common forms of cancer that affect men over 50
• Skin Cancer – can be avoided if you protect yourself from the sun’s harmful rays.

Unlike infectious diseases like AIDS or the flu, cancer is not contagious – it does not spread from one person to another.

Symptoms

Doctors and scientists have found out that there are some symptoms that are typical of cancer. Victims feel pain, sometimes lose weight and become tired or they may feel a change in their skin.

Each form of cancer also has other special symptoms: Blood in your urine may be a signal of bladder or prostate cancer. Lumps in a woman’s breast may mean breast cancer. A cough that does not go away and stays for weeks or months may be the first warning signs of lung cancer.

Causes of Cancer

Scientists do not really know why cancer cells start to grow. They sometimes lose their ability to control their own growth. This is because DNA may be damaged. Doctors, however, have found out that there are many factors that cause cancer. Many forms of cancer are caused by our environment. For example, if you expose yourself to the sun’s rays without any protection for too long, chances of getting skin cancer will become higher.

Smoking cigarettes can cause lung cancer or other diseases over a certain time. Being in close contact with chemicals may also increase the risk of getting cancer.

Being exposed to radiation for too long may also cause cancer. This happened when the nuclear power plant at Chernobyl exploded in 1986. Cancer became more common in the region for years on.

Other types of cancer are not caused by our environment. They come from our genetic material. We inherit it from our parents or grandparents.

Cooling towers of a nuclear power plant. Higher levels of radiation may lead to more cancer cases.
Image : Frettie, CC BY 3.0, via Wikimedia Commons

Cancer Prevention

About 70% of all cancers are caused by environmental factors and our lifestyle. The easiest way of preventing cancer is to avoid certain dangers.

• Protect your skin when you are in the sunshine by using skin creams or lotion on your body.
• Do not smoke.
• Do not drink too much alcohol.
• Eat a lot of fresh fruits and vegetables.
• Go to the doctor regularly for medical checkups.
• Eat wholegrain breads or cereals.

Cancer Treatment

There is no real cure for cancer. But if you go to the doctor early enough it may be treated successfully.

About a hundred years ago people who developed cancer were certain to die. Today, medicine has made so much progress that about half of all cancer patients can be treated successfully depending on the form of cancer.

Surgery

If a cancer is only in one place doctors can remove tumours by surgery. Antibiotics and blood transfusions make cancer surgery more successful than in past times.

In many cases a pathologist examines cancer cells during an operation and then decides how much tissue must be removed. Very often, healthy tissue around the tumour is also taken away in order to make sure all cancer cells are removed.

Radiation

The discovery of X-rays has led to a treatment called radiotherapy. When surgery is too dangerous or risky radiotherapy is a good alternative. In this form of treatment X-rays or gamma rays are beamed directly at the tumour. Cancer cells are killed off and do not multiply any more.

Chemotherapy

If a cancer has already spread to other parts of the body or has invaded other organs doctors use chemotherapy. Chemicals are injected into your body or you take them orally. They then travel throughout your body and kill off cancer cells wherever they find them. Often, a combination of drugs is used because some drugs reduce the size of cancer tumours only for a short time.

This form of treatment can be very risky because the chemicals may destroy healthy stem cells if they are too strong.

Other forms

Recently , new forms of treatment have been discovered and tried out. Immunotherapy strengthens the immune system of the body by producing antibodies.

Gene therapy is a very new form of cancer treatment. New, healthy genes are inserted into the tumour to help fight the disease.

Whatever form of treatment is chosen some side effects always occur. Surgery, for example, may lead to the loss of an organ, like a woman’s breast that must be removed.

During radiotherapy or chemotherapy many cancer patients lose their hair, develop bad skin and become more tired. Other side effects include bleeding, infection, vomiting or diarrhea. Sometimes people who have been treated with cancer become infertile – they can’t have children any more.

Researchers and scientists have been working hard to find a cure for cancer. Governments around the world have been spending a lot of money over the past decades to find better ways of fighting this disease.

Radiotherapy for cancer
Image : Jakembradford, CC BY-SA 4.0,
via Wikimedia Commons

Global Facts

Here are some global facts about cancer.

• One in three of us will be diagnosed with cancer during our life
• Each year more than 7 million people around the world die of cancer.
• Cancer accounts for 13% of all deaths worldwide
• Lung cancer is the most common form of cancer (1.3 million deaths per year)
• Tobacco use is the greatest risk factor for cancer
• More than 70% of all cancer deaths occur in low and middle income counties.

New cancer cases per year

Breast Cancer

Cancer in males

Video

Cancer 101

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New cancer treatment – Multiple Choice cloze
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Blood is an important fluid that keeps us alive. We cannot live without it. The heart pumps blood to all parts of the body and brings them oxygen and food. At the same time blood carries all the substances we don’t need away from us. Blood fights infections, keeps our body temperature the same and carries chemicals that control body functions. Finally, blood has substances that repair broken blood vessels so that we don’t bleed to death.

Image: von Clker-Free-Vector-Images via Pixabay

What blood is made of

Blood is a mixture of fluid and solid matter.

Plasma is the liquid part of our blood. It makes up about 50 – 60 % of it. Plasma consists mostly of water but many other substances are in it. It contains dissolved food, chemicals that control our growth and do other jobs, proteins, minerals and waste products.

Red blood cells look like flat round discs. They contain haemoglobin, a protein that carries oxygen to the body and gives blood its red colour. Each drop of blood has about 300 million of these red cells.

White blood cells, also called leukocytes, fight infections and harmful substances that invade the body. Most of these cells are round and colourless. They have different sizes and shapes. White blood cells are not as numerous as red ones. For every 700 red blood cells there is only one white blood cell.

Platelets are tiny bodies that are much smaller than red blood cells. They stick to the edges of a cut and form blood clots to stop bleeding. The blood of a normal adult has about 2 trillion platelets.

Blood components

Image (altered) : Alan Sved, CC BY-SA 4.0,
via Wikimedia Commons

How blood works in our body

The circulatory system carries blood to all parts of your body. The heart pumps blood through big blood vessels called arteries and veins. In our body there are also millions of small blood vessels called capillaries. Oxygen, food and other substances pass through the thin walls of these capillaries into the tissue.

When you inhale air oxygen passes through your lungs and and is picked up by haemoglobin which transports it to your whole body. It is released into cells which produce energy. In return, cells produce carbon dioxide, which enters your blood stream and is transported back to your lungs where it is exhaled.

Food also reaches your body by means of blood. It is digested in your stomach and important substances like fat, sugar, proteins, vitamins and minerals are separated. These nutrients enter your blood stream and are moved to the cells and muscles where they are needed in order to give you energy or fuel. The work of the muscles and other tissue creates heat. Blood is the transporting system which carries heat throughout your body and warms you. The things that you don’t need are transported to your intestines and kidneys and leave your body again.

White blood cells play an important role in your immune system. When harmful substances invade your body an alarm goes off and white blood cells are activated. Then they work to destroy the invaders. They fight off viruses, harmful bacteria and begin anti-body production.

Blood also carries hormones to places where they are needed. When a hormone reaches a part of the body it controls growth, how the body uses food and other things.

You would bleed to death from a small cut if your blood didn’t clot. When a blood vessel breaks platelets rush to the damaged area and stick to one another , forming a plug.

The body’s circulatory system
Image (modified) : Termininja, CC BY-SA 3.0, via Wikimedia Commons

Blood supply

Blood cells come from bone marrow. They begin as stem cells and then develop into red or white blood cells, or platelets. They don’t live forever and must be replaced by new ones. Red blood cells live an average of 120 days before wearing out. Then they are captured and destroyed in the liver and spleen. Platelets live only for about 10 days.

The amount of blood in your body depends on your size, weight and the altitude at which you live. An adult who weighs 80 kg has about 5 litres of blood, a 40 kg child about half the amount. People who live in high areas where the air is thinner need more blood to deliver more oxygen to the body.

High-altitude training in the Swiss Alps
Professional athletes often carry out training in mountain regions. Such training produces more red blood cells, which can then carry more oxygen to other parts of the body.
Image: Christof Sonderegger von Photoplus.ch, CC BY-SA 3.0,
via Wikimedia Commons

Blood groups

Blood groups are very important in order to find out if a person can donate blood or receive blood in case of an accident or another disease. Almost everyone’s plasma has antibodies that may not work together with another person’s blood.

There are four main blood groups :

• Type 0 is the most common blood group. In an emergency, type 0 blood can be transfused to anybody.
• Type AB is the most seldom group. People with this blood group can receive any other blood in case of an emergency.
• Type A can only be received by donors with A or 0.
• Type B can only be received by donors with B or 0.

Blood groups are very important in order to find out if a person can donate blood or receive blood in case of an accident or another disease. Almost everyone’s plasma has antibodies that may not work together with another person’s blood.

There are four main blood groups :

• Type 0 is the most common blood group. In an emergency, type 0 blood can be transfused to anybody.
• Type AB is the most seldom group. People with this blood group can receive any other blood in case of an emergency.
• Type A can only be received by donors with A or 0.
• Type B can only be received by donors with B or 0.

Blood transfusion

If an adult suddenly loses a litre or more of blood they may die unless the blood in their body can be replaced. Over the years blood transfusions have saved countless lives. Transfusions can also help patients who cannot produce enough blood cells to survive. They also help during operations when patients lose some blood.

Blood banks collect blood from donors and put it in sterile bags. It is cooled down and can be stored for up to 50 days. Laboratory workers screen blood for infectious diseases like AIDS and hepatitis. Only clean and safe blood can be given to patients.

Image:BruceBlaus. When using this image in external sources it can be cited as:Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436., CC BY 3.0,
via Wikimedia Commons

Blood diseases

When a person suffers from anaemia there are not enough red blood cells to supply the body with the oxygen it needs. Leukemia is a kind of cancer of the bone marrow, in which not enough or abnormal white blood cells are produced. Without white blood cells diseases can enter your body without being controlled.

When your body does not have enough platelets blood cannot clot well. Even small injuries can lead to a loss of blood because bleeding doesn’t stop.

Image: (modified) Mikael Häggström,
Public domain, via Wikimedia Commons

fatigue = to become very tired
shortness of breath = to have problems breathing in a normal way
joint = part of your body that can bend because two bones meet there
swelling = part of your body that becomes larger than normal
lymph node = a small rounded swelling in your body through which a liquid passes before entering your blood system
enlargement = when something gets bigger
spleen = an organ near your stomach that controls the quality of your blood

Videos

Blood Components and Blood Cells
The Circulatory System
Blood Groups
Blood Transfusions

Exercises

Multiple Choice Test
Words and Definitions 1
Words and Definitions 2
Unscramble the words
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Match the sentence parts
Blood and the circulatory system – Missing word cloze
New blood test to detect cancer – Word formation
Crossword 1
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