According to the World Health Organization (WHO), health is a State of complete physical, mental and social well being and not merely the absence of disease. It means proper functioning of the body and the mind.
People enjoying good health are more cheerful, energetic, full of life, more efficient at work and therefore more productive. The three different dimensions of health are together referred to as health triangle.
The various practices that help in maintaining health constitute hygiene. To keep free from diseases and maintain good health you need to practice proper hygiene.
Adopting hygienic practices and promoting hygiene in the community, school and workplace prevent spread of many infectious diseases. Hygiene deals with both personal health as well as community health.
A balanced diet is one containing carbohydrates, proteins, fats, vitamins, minerals and fibres in correct proportion to meet the nutritional requirement of a person at a certain age and doing a certain amount of physical work. The energy requirement for moderately active adolescent (teenage) boy is about 2200 to 2400 Calories where as for adolescent girls it is 2000 Calories.
Following are some necessary hygienic habits:
Regular toilet habit: Regular bowel movement keeps us free of waste generated within the body.
Washing hands before eating: Our hands may carry many disease causing germs and therefore we must wash them with soap or ash before taking food.
Bathing regularly and wearing clean clothes: Bathing regularly keeps our body free of dirt, body lice and germs.
Cleaning the teeth: When we eat, some food particles may remain stuck to our teeth. These particles attract germs which harm our gums and teeth, and cause bad breath. Brushing teeth every morning and after dinner helps in their removal.
Washing hair, cleaning eyes, ears and nails: Regular washing and combing of hair, and washing eyes with clean water helps to keep the germs away. Nails of both hands should be clipped regularly. Nail biting is unhygienic and must be avoided.
A condition that interferes with the normal functioning of the body is called a disease. It can be as mild as a cold, sore throat or as serious as cancer or tuberculosis.
Communicable diseases spread from one person to another by the entry of pathogens (disease causing organisms). Pathogens enter our body through various means, and then multiply there. They can be transferred from one person to another by direct or indirect contact.
We are exposed to a large number of disease causing agents every day. Our body is able to ward off most of these foreign agents. This overall ability of the body to protect itself against the foreign agents including the disease causing organisms is called immunity. It is of two types:
- Innate immunity
- Acquired immunity
Innate immunity is present from the time of birth and provides protection against the entry of any foreign agent into our body. Skin and the mucous membranes prevent entry of foreign agents into the body. Hydrochloric acid in the stomach kills the germs that reach the stomach. White blood cells (WBC) engulf foreign particles and destroy them.
Acquired immunity develops during one’s life time by producing antibodies in response to foreign bodies termed antigens. Each antigen is recognised by a specific antibody. Antibodies’ are proteins produced by lymphocytes (a type of WBC), against specific antigen. Antibodies remember and recognize the infective agents that have once attacked the body and recognize and kill them when they enter the body again. This is called the memory of the immune system and is the basis of immunization programme. Such as against mumps or measles.
Whenever we fall ill and visit a doctor, he has to ascertain the nature of the disease, damage caused and its extent. For this certain tests or examinations such as blood tests, x-ray, ECG or MRI etc are recommended.
X-ray radiography is one of the oldest and still the most widely used diagnostic imaging technique. It uses a beam of x-rays (electromagnetic waves of very short wavelength) directed at the body part to be examined.
The rays pass through the body part to be examined and fall on an x-ray sensitive film and produce a shadowy image of the dense parts of the body. Dense structures like tumours absorb the x-rays the most and so appear as light areas on the adiograph (the film). Hollow organs, fat tissues absorb x-rays to a lesser extent and appear as dark areas.
Ultrasound imaging technique or sonography is a simple, non invasive technique based on ultrasound (frequencies above 20 KHz or 20,000 cycles per second) that are beyond the range of human hearing. Diagnostic ultrasound uses 1-15 MHz (106 cycles/sec = 1 MHz).
The body is probed with precise sequence or pulses of ultrasound waves that traverse through different body tissues. Sound waves get reflected and scattered to different extent by the body tissues depending on their densities. These reflected waves are received back and processed by a computer to construct visual image of the outline of the body organ under investigation.
To obtain the image, a single hand held device is used both to emit the sound waves and to pick up the reflected waves. The device is easy to move around and is slid across the skin overlying the area to be imaged.
MRI (Magnetic resonance imaging) is a technique that produces high contrast image of our soft tissues (Muscles, cartilage, ligaments, tendons, blood vessels) an area in which x-rays and other imaging techniques are weak.
For MRI, the patient is positioned at the centre of a machine which has powerful magnets. It creates a magnetic field. The protons (of Hydrogen molecule) align themselves in this magnetic field. When the magnetic field is turned off, energy is released by the protons.
This energy is received by sensitive detectors and is fed to powerful computers to generate extraordinarily detailed images from any part of the body. Image of different tissue can be contracted depending and their water content. Patients, who have metal implants, pace-makers, etc. cannot be imaged.