Common diseases

for class 12 busineess studies

1. INTRODUCTION
Health-It can be defined as a state of complete
physical, mental and social well-being. When
people are healthy, they are more efficient at
work.
Health is affected by:–
•Genetic disorders –heritable defects of parents
to offspring.
•Infections
•Life style including food and water we take,
rest and exercise we give to our bodies, habits
that we have or lack etc.
Diseases can be broadly grouped into infectious
and non-infectious. Diseases which are easily
transmitted from one person to another are
called infectious diseases. Among non-
infectious diseases, cancer is the major cause of
death. Drugs and alcohol abuse also affect our
health adversely.

2. Common Infectious Diseases in Humans
Pathogen-Pathogens are the parasites that
enter the human body through various means,
then multiply, and interfere with normal vital
activities.
Bacterial Diseases
Bacteria are prokaryotic, unicellular
microorganism that are found everywhere.
Bacteria are found in the soil, water and air.
Bacteria are also found on human skin and in the
digestive tract-
•Bacteria can enter other body systems and cause
infections or disease.
•Bacteria can enter the body through a cut in the
skin, the respiratory tract or the digestive tract.
1)Typhoid:-
•Pathogen −Salmonella typhi
•Spreads through −Contaminated food and
water
•Site of infection −Small intestine
•Symptoms −High fever, stomach pain,
headache, loss of appetite, constipation,
and intestinal perforations in severe cases.

3. 2) Pneumonia:-
•Pathogens −Streptococcus
pneumoniaeand Haemophilus
influenzae
•Spreads through −Droplets/aerosols
released from infected person, sharing
of glasses or utensils.
•Site of infection −Alveoli (gets filled
with fluid, difficulty in breathing).
•Symptoms −Fever, chills, cough,
headache, lips and nails become grey in
severe cases.

4. Viral Diseases
A Virus is a small particle that contains
proteins and heredity material (DNA or
RNA), but is not alive.
•The virus is surrounded by a protein coat,
or capsid.
•A virus particle can not eat, metabolize
food and can only reproduce inside a cell.
•Outside the cell, the virus particle does
nothing and remains inactive.
1)Common cold:-
•Pathogen −Rhino viruses
•Site of infection −Nose and respiratory
passage.
•Spreads through −Droplets released
from coughing or sneezing, or
contaminated objects.
•Symptoms −Nasal congestion and
discharge, sore throat, cough, headache,
tiredness.

5. SOME COMMON UPCOMING
VIRUS DISEAES
Ebola Virus
Ebola virusis a very dangerousvirus. It causes
ahemorrhagic fevercalledEbola virus disease.
"Hemorrhagic" means that the victim will bleed a
lot, inside and outside their body.
Humans may spreadthe virus to other humans
through contact with bodily fluids such as blood.
Initial symptomsinclude fever, headache, muscle
pain and chills. Later, a person may experience
internal bleeding resulting in vomiting or coughing
blood.
zika Virus
Zika virus disease is caused by a virus transmitted
primarily byAedes mosquitoes.
People with Zika virus disease can have symptoms
including mild fever, skin rash, conjunctivitis,
muscle and joint pain, malaise or headache. These
symptoms normally last for 2-7 days.
There's no vaccine or specific treatment for the
disease.

6. 1) Ringworms:-
•Pathogens −Genera Microsporum,
Trichophyton, and Epidermophyton
•Spreads through −Towels, clothes,
comb (Fungus is acquired from soil)
•Symptoms −Appearance of dry,
scaly lesions on various body parts
with intense itching.
FungalDiseases

7. Protozoan Diseases
•Protozoan's are unicellular or colonial
organisms.
•Many animal-like and fungus-like protests
can cause human diseases including African
sleeping sickness, malaria and yellow fever.
•Some protists require an animal intermediate,
such as a mosquito, to enter the body.
•Sometimes protists enter the body through the
digestive tract from contaminated food or
water.
1)Malaria:-
•Pathogen −Protozoan Plasmodium vivax.
•Vector −Female Anophelesmosquito
•Symptoms −Head aches, muscle pain, high
fever. During fever the patient feels chill
and shivering.
•Mode of spread-This disease spreads by
the bite of infected Anopheles mosquito.
Only the female Anopheles is capable of
spreading the disease because it sucks the
blood of man.

8. Life Cycle of Plasmodium
•Plasmodiumrequires two hosts to complete
its life cycle.
•When female Anophelesmosquito bites a
healthy human being, it releases Plasmodium,
which lives in its body as sporozoite
(infectious form).
•The parasites multiply (asexual
reproduction) in the liver cells and finally
burst the liver cells. Sporozoites are released
in blood.
•Parasites enter RBCs and further multiply
(asexual reproduction) here and finally burst
RBCs also.
•Bursting of RBCs is accompanied by release
of a toxic substance called haemozoin
(associated with fever and chills).
•In the RBCs, only sporozoites change into
gametocytes (sexual stage). Gametocytes
multiply.
•When the diseased person is bitten by a
female Anophelesmosquito, gametocytes are
introduced into the mosquito.

9. •Gametocytes fertilize and develop inside the
intestine of mosquito to form sporozoites.
•Sporozoites are stored in the salivary glands
of mosquito and are released into the healthy
person who is bitten by this mosquito.

10. 2) Amoebiasis:-
•Pathogen −Entamoeba histolytica
•Vector −Housefly
•Site of infection −Large intestine
•Symptoms −Constipation, abdominal
pain, cramps, stools with mucous, and
blood clots.

11. Diseases Caused by Worms
1)Ascariasis:-
•Pathogen −Round worm, Ascaris.
•Spreads through −Water, vegetables,
fruits contaminated by faeces of
infected person.
•Symptoms −Internal bleeding,
muscular pain, fever, anemia, blockage
of intestinal passage.

12. 2) Elephantiasis (filariasis):-
•Pathogen-Wuchereria(W.malayiand
W.bancrofti)
•Spreads through −Bite of female
mosquito vector
•Symptom −Chronic inflammation of
the organs, usually the lymphatic
vessels of lower limb.This enlargement
of legs gives the disease its name as
Elephantiasis.

13. Immunity
What is immunity?
The ability of body to fight the
disease-causing organisms is
called immunity.
Types of immunity
Immunity is of two types −
1) Innate immunity
2) Acquired immunity

14. AIDS
AIDS (Acquired Immuno Deficiency
Syndrome) ,Caused by HIV (Human
Immunodeficiency Virus) [HIV is a
retrovirus (RNA virus)].
Transmission of HIV occurs through:-
•Sexual contact with infected person.
•Sharing infected needles (as in case of
intravenous drug abusers).
•Transfusion of contaminated blood
Infected mother to child through
placenta.
Time lag between infection and
appearance of symptoms −Few
months to many years (5-10 years).

15. How does AIDS infection spread?
When HIV virus enters the host cell, the
virus enters into macrophages, where RNA
replicates and forms viral DNA by the help of
enzyme reverse transcriptase.
The viral DNA gets incorporated into the
host cell’s DNA and directs the infected cells
to produce daughter viruses.
The macrophages continue to produce
virus that enters the helper T-lymphocytes.
Thus the number of helper T-lymphocytes
progressively decreases in the body and
weaken the immune system.
Even infections which could be overcome
easily start aggravating.
Diagnosis of AIDS :−By ELISA (Enzyme
Linked Immuno Sorbent Assay).
Treatment :−No permanent cure;
antiretroviral therapies can prolong the life
of patient.

16. Symptoms of AIDS

17. Prevention of AIDS:-
•Ensuring use of disposable syringes.
•Screening blood from blood banks.
•Advocating safe sex.
•NACO (National AIDS Control
Organization) and many NGOs are
doing a lot to create awareness
among people.

18. Cancer
The process of development of cancer
is called oncogenic transformation.
•Cancer cells divide continuously to
give rise to mass of cells (tumor).
•Tumor caused by abnormal and
uncontrolled cell division.
Tumor are of 2 types −
1.Benign Tumor
2.Malignant Tumor

19. 1)Benign tumor :−
Remain confined to their original
location and do not spread.
2)Malignant tumor:−
Cells divides and invades new
locations by getting transported
through blood to distant sites.
Metastasis:-Property of malignant
tumor to invade the distant body
parts, thereby initiating formation of
new tumors.

20. Causes of cancer:-
•Carcinogens −Physical, chemical, and biological
agents that cause cancer Example -ionizing
radiations (X-rays and gamma rays), non-ionizing
radiations (UV)
•Oncogenic (cancer-causing) viruses−They have
viral oncogenes (cancer-causing genes).
Sometimes normal genes in our body called proto-
oncogenes get converted into cellular oncogenes that
cause cancer.
Diagnosing cancer:-
•Biopsy−Suspected tissue is cut into thin sections
and examined microscopically
•Radiography-CT scan (computed tomography), and
MRI (Magnetic resonance imaging) are techniques
of diagnosing cancers.
•C T Scan−3-D imaging of internals of an organ is
generated by X-rays.
•MRI Scan−Pathological and physiological changes
in a living tissue are detected by using magnetic
fields and non-ionizingradiations.
•Immunological and molecular biological diagnostic
techniques can all be used to detect cancers.
•Identifying certain genes, which make an individual
susceptible to cancers, can help to prevent cancers.

21. Treatment of Cancer:-
1.Radiotherapy−Tumor cells are
irradiated to death. Also, proper care is
taken for protecting surrounding
normal tissues.
2.Chemotherapy−Drugs specific for
particular tumors are used to kill
cancer cells. They have side effects
such as hair loss, anemia, etc.
3.Immunotherapy−Biological response
modifiers such as α-interferons are
used. They activate the immune system
of patient and helps in destroying the
tumor.
4.Surgical–Cancerous tissues are
surgically removed.

22. Symptoms of Cancer:-
•Weight loss
•Fever
•Fatigue
•Pain
•Skin color changes
•Loss of Appetite
•Nausea

23. Prevention of Cancer:-
•Don't use tobacco.
•Eat a healthy diet.
•Maintain a healthy weight
and be physically active.
•Get regular medical care.

24. Drugs
Commonly Abused Drugs:-
1) Opioids (Heroin)
2) Cannabinoids
3) Cocaine
4) Nicotine
5) Drugs Normally Used as Medicines:-
•Drugs like barbiturates, amphetamines,
benzodiazepines, LSD (Lysergic acid diethyl
amides) are used as medicines to help patients
with mental illness and insomnia.
•Morphine: It is a pain killer which is used for
patients who have undergone surgery, but it is
also abused.
Alcohol / Drug Abuse:-
Alcohol / drug abuse normally starts in Adolescence.
Adolescence is the period during which the child
becomes matured. It is between 12–18 years of age.

25. Investigation
1)Typhoid:-
Prevention-Preventing typhoid is all about
avoiding contaminated food and water.
•Peel all fruit and vegetable skins before eating.
•Cook all food thoroughly and eat it while it's hot.
Treatment-With appropriate antibiotictherapy,
there is usually improvement within one to two
days and recovery within 7 to 10 days.
•Vaccination.
Age group more prone to Typhoid -It is common in
humans of the 1 to 15 years age group.
2) Pneumonia:-
Prevention-Proper vaccination.
•Good hygiene
•Don't smoke
Treatment-With appropriate antibiotictherapy.
Age group more prone to Pneumonia-Infants
who are 2 years old or younger and people who are
65 years old or older.

26. 3) Common cold:-
Prevention-Wash your hands often.
•Cover your mouth and nosewhen sneezing or
coughing.
Treatment-Pain relievers
•Decongestant nasal sprays
•Cough syrups
Age group more prone to Common cold-It is
common in children of the 6 to 10year old.
4) Ring Worm:-
Prevention-Keep skin and feet clean and dry.
•Avoid touching pets with bald spots.
•Items such as clothing, hats, brushes and towels
of an infected person should not be shared with
others
Treatment-Antifungal creams or ointments
•Antifungal tablets
Age group more prone to Ring Worm-Equally
common in all age groups.

27. 5) Malaria:-
Prevention-Eradication of vector
•Keeping the surrounding clean
Treatment-With appropriate antibiotictherapy.
•Vaccination
Age group more prone to Malaria-Children under
5 years of age.
6) Amoebiasis:-
Prevention-Proper disposal of faecal matter of the
patient.
•Vegetables and fruits when used raw, should be
thoroughly washed.
•Water should be boiled before drinking.
Treatment-With appropriate antibiotictherapy.
Age group more prone toAmoebiasis-Most
commonly affects young adults(ages18–35 years).

28. 7) Ascariasis:-
Prevention-The disposal of human faeces
by underground sewer canals is an efficient
measure to prevent the spread.
•Washing of vegetables and fruits before
eating help to keep away the eggs of the
worm.
Treatment-Medications
•Surgical intervention
Age group more prone to Ascariasis -It is
most common in children of 10 years old or
younger.
8) Elephantiasis (filariasis):-
Prevention-Eradication of vector.
Treatment-Surgery
•Diet and activity.
Age group more prone to Elephantiasis-It
is observed in all age groups from 10 years
and above.

29. BIBLIOGRAPHY
This project is made by using
the analytical data provided by
the following reference books
and websites:
1.Wikipedia (Encyclopedia)
2.Google
3.Google Images
4.NCERT Textbook of XII