"Why do we fall ill"

 Topics to be covered in this lesson:-

Introduction 

Health and its failure

• The significance of 'health'
• Personal and community issues both matter for health
• Distinction between "healthy" and "Disease free"

Disease and it's causes 

• what does disease look like?
• Acute and chronic disease
• Chronic diseases and poor health
• Causes of diseases
• Infectious and non- Infectious causes

Infectious diseases

• Infectious agents
• Means of spread
• organ specific and tissue specific manifestation
• Principles of treatment
• Principles of prevention

Introduction:-

Health and its failure:-

What is health?

• A state of being well enough to function well physically , mentally and socially.

Requirements for healthy life cycle:-

• Balance diet
• Clean and hygienic environmental
• Proper exercise
• Proper sleep 
• Social equality and harmony

What is meant by disease?

• Dis--> disturb and Ease --> comfort
• Disease means something is wrong with our body and we feel unwell.

Reasons:- 

• Malfunctioning of body,
• Unbalance diet,
• Dirty and unhygienic conditions,
• Lack of exercise,
• Poor sleep,
• Poverty

Distinction between healthy and disease free:-

Healthy:- 

1.  It is a state of complete physical, mental and social well being
2.  It depends upon the individual as well as physical and social environment.
3. A healthy person will be disease free.
4. Healthy person is energetic and able to perform as per requirement.

Disease free:-

1. It is a state of absence of comfort in any part of body ,
2. It is related to the individual only
3. A disease free person can be healthy or unhealthy,
4. Performance of a disease free person depends upon environment and personal attitude.

Disease:- 

• Dis - Disturbance, Ease - Comfort
• Disease results in a change in either the functioning or appearance of one or more system of the body for the worse.
• Example:- headache,fever etc.

Disease : Sign and symptoms

Symptoms:- 

• symptoms of disease are the things we feel as being 'wrong'
• Symptoms indicate that there might be a disease

Signs:-

•  signs of a disease are the things a. Doctor looks for on the basis of symptoms .
• Signs indicate presence of a particular disease.

Acute Vs Chronic diseases:-

Acute diseases:- 

• Disease which last for very short periods of time.
• Example:- common cold, cough, flu, tonsillitis, appendicitis, headaches.

Chronic diseases:- 

• Diseases which last for a long time
• Example:- Asthma , Diabetes, Glaucoma (eye disease: optic nerve damage) , Allergy

Causes of disease:- 

• There are many levels of cause of a disease

 1. Immediate cause:- 

• The first cause identified when a person is suffering from a disease
• Mostly the immediate causes are the infecting organisms like bacteria, virus , fungi etc.
• Note :- Not all disease 's immediate cause is micro organisms
• Example:- cancer, high blood pressure

2. Contributing cause:- 

• Reason identified after the immediate cause.
• Contributing cause along cannot cause the disease
• Example:-
• Cholera is caused by Bacteria ( immediate cause)
• Here contributing causes are lack of cleanliness, poverty, Genetically weak.
• So contributing cause + Immediate cause together causes the disease.

Infectious Vs Non Infectious diseases:-

Infectious disease:-

• Diseases for which microbes are the immediate cause.
• Infection can spread from one person to another
• Infectious agents:- microbes
• Termed as communicable / contagious diseases.
• Example:- Flu, common cold, cough , measles.

Non Infectious diseases:- 

• Diseases for which microbes are not the cause
• Does not spread from one person to another.
• Internal ,non Infectious causes (like genetic causes) 
• Example:- cancer, diabetes , high blood pressure
• Termed as non- communicable / non contagious diseases

Infectious agents:- 

• Many categories of microbes can act as infectious agents
• Virus , Protozoa, Bacteria, worms, fungi

Diseases caused by different infectious agents:-

Virus :- 

• common cold, influenza, dengue,AIDs (Acquired Immuno-Deficiency Syndrome)

Bacteria:- 

• Typhoid, Cholera, Tuberculosis (TB) ,Anthrax

Fungi :-

•  Skin infections

Protozoa:- 

• Malaria, Kala Azar 

Worms:- 

• stomach ,Interesting infection,  Elephantiasis

How does knowledge of infectious agents helps to decide treatments?

• Different microbes have different like process,so different drugs affect these different life processes.
• Example:- Bacterial infection be Viral infection.

Means of spread of Infectious diseases:-

• Ways by which infection can spread from one person to another.
• Some ways are :- air, water,Direct and indirect contact, sexual contact, vectors

Air:- air borne diseases

• Droplets thrown by an infected person during coughing/ sneezing .
• Example:- common cold , pneumonia, tuberculosis

Water :- Water borne diseases

•  Excreta of infected person gets mixed with drinking water .
• Example:- Cholera, typhoid, hepatitis A 

Direct and Indirect contact:-

Direct contact:- touch , kiss, hand shake

Indirect contact:- Things used by infected person

Example:- Ringworm, Conjunctivitis (eye infection) , head lice, skin infections

Sexual contact:- 

• Sexual act with an infected person. Example:- AIDs , Syphillis
• AIDs spread only by sexual contact, mother to child and blood transfusions and not by air, water and direct and indirect contacts

Vectors:- 

• Insects /animals which act as carrier of infection from infected to healthy person are called vectors.
• Example:- Malaria,Dengue, Chikungunya(mosquitoes) Rabies , a viral infection (dog)

Terminologies related to infection:-

Pathogen:-

• Microbes that cause diseases
• Example:- Bacteria, viruses

Host:- 

• Organism on which microbes attacks/ infects 
• E.g. Human Beings 

Parasite:-

• Organism that live in/on the body of host and derives nutrients from host, not necessarily kill the host 
• E.g.:- Tapeworms, lice

Note:- 

• Pathogen always cause disease to host 
• Parasite may or may not cause disease to host.

Vectors:-  

• Animals which introduce parasites into the host body . Example:- Mosquito.

How do the infectious agents affect our body?

• Target side is decided by the point of entry 
• If it is through mouth it attack on gut line or liver
• If it is bacteria ,then it attack through gut lining and cause Typhoid
• If it is virus, then it attack on Liver and cause Jaundice.

Now if the entry point is nose then it attack on lungs and cause breathing problems such as Asthma.

• Can also spread from one part to different body parts  
• Example:- Mosquito bite --> Malaria --> Brain fiver.

Some agents also target the immune system of the body 

Immune system:-  

• Network of cells that protects the body from foreign particles 
• A group of cells of the affected tissue is employed to kill off the microbes . This process is known as Inflammation.

Consequences of Inflammation:-

•  Pain , Swelling, Fiver
• For example:- In AIDs , virus attack the immune system.

Principles of treatment of an Infectious disease:- 

Two ways to treat :- 

1. Reduce the effect:- 

• Take medicine to reduce pain, fiver. 
• Take rest to conserve energy.

2. Kill the cause:- 

• Take appropriate medicines to kill microbes

Principles of prevention:- 

General ways of prevention:- 

• Prevent exposure to microbes 
• Avoid overcrowded living conditions,
• Clean drinking water.

• Public as well as individual hygiene
• Proper nourishment and food to keep the immune system strong enough

2.specific ways of prevention:- vaccination

Vaccination:-

•  Process in which vaccine is given to improve the immunity of the body against a specific disease

Vaccine :- 

• Biological preparation that resembles a disease causing microbes 
• Made of dead or very weak microbes

Vaccination success:- 

• Smallpox is eradicated 
• Diseases like polio , tetanus, measles have been reduced to a large extent

Effective vaccination :- 

• Effectiveness of vaccines varies with the type of disease.
• For older people , larger doses are needed .
• Vaccination schedule has to be followed.

Prevention is better than cure because:-

• During disease, body functions are damage ,
• Treatment takes time ,
• Diseased person become source for other person.
• So prevention is better than cure.

Thankyou :-)