Why Do We Fall Ill Short Notes | Class 9 Science
Introduction
In communities of humans, health and illness are extremely complicated problems with numerous interrelated causes.
Health
Health is often defined as a state of complete physical, mental, and social well-being, rather than merely the absence of disease or disability. It encompasses a variety of factors that affect an individual's overall functioning and quality of life.
Differences between Being Healthy and Disease-free
Being Healthy | Being Disease-free |
| It is a state of being well enough to function well physically, mentally and socially. | It is a state of absence from diseases. |
| It refers to the individual, physical and social environment. | It refers only to the individual. |
| The individual has good health. | The individual may have good health or poor health. |
Disease and Its Causes
- A disruption in the body's regular processes is referred to as a disease. It may have an impact on a person's social, mental, and physical health.
(i) Acute Disease: Acute diseases are defined by their quick onset and short duration. These illnesses are frequently severe and last anywhere from a few days to a few weeks. Acute bronchitis, influenza, and the common cold are a few examples.
(ii) Chronic Disease: A chronic disease lasts for a long period, frequently the entirety of a person's life. These illnesses take time to appear and impact a person's health for a long time. Diabetes, high blood pressure, and arthritis are a few examples.
(ii) Chronic Disease: A chronic disease lasts for a long period, frequently the entirety of a person's life. These illnesses take time to appear and impact a person's health for a long time. Diabetes, high blood pressure, and arthritis are a few examples.
Infectious and Non-infectious Diseases
(i) Infectious Disease: Microorganisms like bacteria, viruses, fungi, and parasites are the cause of these illnesses. Air, water, physical contact, and vectors (like mosquitoes) are some of the ways they can spread from one person to another.
(i) Non-Infectious Disease: These illnesses can be brought on by a number of things, such as environmental, lifestyle, and genetic factors. They can have long-term health effects and are frequently chronic.
(i) Non-Infectious Disease: These illnesses can be brought on by a number of things, such as environmental, lifestyle, and genetic factors. They can have long-term health effects and are frequently chronic.
Infectious Agent and disease
- Bacteria: Single-celled microorganisms called bacteria are responsible for cholera, typhoid fever, and tuberculosis.
- Viruses: Viruses are smaller than bacteria and are only capable of reproducing within their host's cells. AIDS, influenza, and the common cold are a few examples of viral diseases.
- Fungi: These microorganisms are responsible for ringworm and athlete's foot infections.
- Protozoa:Single-celled organisms called protozoa are responsible for illnesses like kala-azar and malaria.
- Helminths: Helminths are parasitic worms that can lead to intestinal worm infections and elephantiasis.
Antibiotics
- Microorganisms (like bacteria and fungi) produce substances called antibiotics that either stop the growth of other microorganisms or kill them. Their main purpose is to treat infections caused by bacteria.
- Antibiotics do not work against viruses; they only work against bacteria.
Means of Spread Of Infectious Disease
- Air: Infectious diseases such as influenza, TB, and the common cold spread through the air. Tiny droplets containing pathogens are released into the air when an infected person coughs or sneezes, and others may inhale them.
- Water: Contaminated water can spread diseases like amoebiasis and cholera. The pathogens can infect others who drink or use water that has been contaminated by an infected person's excrement.
- Physical Contact: Skin infections and sexually transmitted diseases (STDs) like AIDS and syphilis can be spread by direct contact with an infected person or their bodily fluids.
Vectors:
Vectors are organisms that transfer pathogens from one host to another, which is how some diseases are spread. For instance, ticks can spread Lyme disease, and mosquitoes can spread dengue and malaria.Food:
Food: Infections can also be contracted from contaminated food. Consuming food tainted with pathogens can spread foodborne illnesses such as hepatitis A and food poisoning.
AIDS ( Acquired Immunodeficiency Syndrome)
The retrovirus known as HIV (Human Immunodeficiency Virus) is the cause of AIDS.
Method of transmission of AIDS
- sexual contact
- blood transfusion
- Needlestick Injuries
- Transmitted from infected mother to her foetus.
Prevention of AIDS
- Practice Safe Sex: Have sex with a condom to avoid the risk of HIV transmission.
- Avoid Sharing Needles: Don't share needles or syringes because this will spread HIV through blood.
- Screen Blood Products: Screen blood and blood products adequately for HIV prior to transfusion.
- Mother-to-Child Prevention: HIV-positive women must consult physicians to lower their chances of spreading the virus to their infants through pregnancy, labor, or breast-feeding.
- Routine Testing and Treatment: Routine HIV testing and early treatment with antiretroviral therapy (ART) can suppress the virus and lower the risk of transmission.
Organ-Specific and TIssue-specific Manifestation
(i) Organ-Specific Manifestation
When a disease only affects one organ, it is referred to as an organ-specific manifestation.
Example
- Heart Diseases: Symptoms are chest pain, fatigue, and palpitations.
Liver Diseases: Symptoms like jaundice, swelling of the abdomen, or liver enlargement.
(ii) Tissue-Specific Manifestation
A disease is said to have a tissue-specific manifestation when it affects a particular tissue.
Examples
- Muscle Tissue Damage:Muscle weakness and loss of mass result from conditions like muscular dystrophy, which specifically affect the skeletal muscle tissue.
- Nervous Tissue Damage: Meningitis and other infections that impact the nervous system can cause neurological symptoms, fever, and headaches.
Principle of Treatment
The principles of treatment generally focus on how diseases are managed.
- Reduce Symptoms: Reduce the patient's discomfort by easing their symptoms (e.g., using pain relievers, fever reducers).
- Kill the Cause: Use antibiotics to treat bacterial infections in order to target and eradicate the pathogens that are causing the illness.
Principle of Prevention
• There are two ways of prevention of infectious diseases. They are general ways and specific ways.
1. General Ways
These approaches seek to decrease the risk of infection with infectious agents:
- Public Hygiene: Maintaining hygienic surroundings to avoid diseases.
Safe Drinking Water: Offering clean and safe water to avoid water-borne illnesses.
- Sanitation: Cleanliness in order to prevent vector-borne diseases and dispose of waste correctly.
2. Specific Ways
These strategies emphasize boosting the body's immune system in order to resist infections:
- Vaccination: Vaccinating people against particular illnesses in order to avoid outbreaks.
- Improving Immunity: Maintaining a healthy lifestyle and diet to strengthen the immune system.