Chapter - 13 Why Do We Fall Ill

'Health' is a state of being well enough to function well physically, mentally and socially.
Therefore, for good health.

1. One should be disease free.
2. There should be social equality and harmony which are essential for individual health particularly for social and mental health.

1. Remain away from specific and particular cause for discomfort or disease. For which personal and public cleanliness and good physical environment are necessary.
2. Proper and sufficient food necessary for functioning of cells and tissues of the body.

Common symptoms, which indicate sickness are:

1. Headache,
2. Cough and
3. Loose motion.

Even seeing one symptoms. I will go to doctor.
A single symptom is the sign of a disease. On delaying, it may lead to serious illness. For example, headache may mean meningitis.

Jaundice because it is a chronic disease and takes long time to be cured. Moreover, jaundice affects the whole body and it takes long time to be healthy.

Earth’s atmosphere is different from those of Venus and Mars. This difference lies essentially in their compositions. Earth’s atmosphere is a mixture of nitrogen (79%), oxygen (20%), and a small fraction of carbon dioxide, water vapours and other gases. This makes the existence of life possible on Earth. However, the atmospheres on Venus and Mars mainly consist of carbon dioxide. The amount of carbon dioxide on these planets can range from 95% to 97%.

Infectious disease show a lack of success of the immune system of the body. For the functioning of immune system properly, sufficient nourishment and easily digestible food is necessary for a sick person.

Infection causing microbes travel from patient to person through:

1. Air: Sneezing or coughing since little droplets are thrown which they reach another person through air. Example, common Cole, pneumonia etc.
2. Water: contaminated water carries disease causing microbes which cause infection on its usage. Example, diseases such as cholera.
3. Sexual contact: Diseases such as syphilis or AIDS are transmitted by**ual contact from one person to the other.
4. Animals: These are intermediaries, called vectors, transmitting diseases from a patient to the host. Example, mosquitoes (Female Anopheles mosquito) cause spread of malaria.

1. Preventing over crowing classes,
2. Providing safe drinking water,
3. Cleanliness in the school premises and also in the classroom,
4. Use of handkerchief or towel while an infected student in sneezing or coughing,
5. Use of clean toilets,
6. Not to allows water to stagnate in school or around the school to avoid mosquito breeding,
7. To get vaccinated whenever programmers organized for inoculation against various diseases.
8. Not eating food exposed to flies, mosquitoes etc.

Introduction of mild type of infection (microbes) or killed infectious microbes into the body by vaccination / by other means to activate the immune system against a particular infection / disease is called immunization.

Immunization programme

1. BCG vaccine against tuberculosis.
2. Polio drops against polio.
3. Vaccination against chicken pox.
4. Vaccination against Hepatitis.
5. DPT vaccination against diptheria, pertusis (whooping cough) and tetanus.
6. Immunisation against measles.

Major health problems are

1. Hepatitis,
2. Chicken pox,
3. Tuberculosis and
4. Tetanus

The atmosphere acts as a blanket by performing the following functions:

1. It keeps the average temperature of the Earth fairly constant during day time and even during the course of whole year.
2. It prevents a sudden increase in the temperature during day time.
3. It slows down the escape of heat from the surface of the Earth into outer space during night time.