Common Diseases in Humans
What is Health?
● Health is the state of complete physical, mental, and social well being.
● Health increases productivity and ensures longevity.
Ways to Ensure Good Health
● Balanced diet
● Personal hygiene
● Exercise
● Awareness about prevention and control of diseases
● Proper waste disposal and control of vectors
● Vaccination
Why do Diseases Occur?
● Genetic reasons − Innate deficiencies and inheritable defects
● Infections
● Sedentary life style − Junk food, consumption of alcohols/drugs, lack
of exercise
Pathogenic Diseases
● Pathogens are the parasites that enter the human body through
various means, then multiply, and interfere with normal vital activities.
Bacterial Diseases
● 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
○ Confirmatory test − Widal test
● Pneumonia
○ Pathogens −
Streptococcus pneumoniae
and
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
Viral Diseases
● 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
Protozoan Diseases
● Malaria
○ Pathogen −
Plasmodium
sps. (
P.vivax, P. falciparum, P. malaria
)
○ Vector − Female
Anopheles
mosquito
○ Symptoms − High grade fever, chills
● Amoebiasis
○ Pathogen −
Entamoeba histolytica
○ Vector − Housefly
○ Site of infection − Large intestine
○ Symptoms − Constipation, abdominal pain, cramps, stools with
mucous, and blood clots
Fungal Diseases
● Ringworms
○ Pathogens − Genera
Microsporum
,
Trichophyton
, and
Epidermophyton
○ Spreads through − Towels, clothes, comb (Fungus is acquired
from soil)
What is Health?
● Health is the state of complete physical, mental, and social well being.
● Health increases productivity and ensures longevity.
Ways to Ensure Good Health
● Balanced diet
● Personal hygiene
● Exercise
● Awareness about prevention and control of diseases
● Proper waste disposal and control of vectors
● Vaccination
Why do Diseases Occur?
● Genetic reasons − Innate deficiencies and inheritable defects
● Infections
● Sedentary life style − Junk food, consumption of alcohols/drugs, lack
of exercise
Pathogenic Diseases
● Pathogens are the parasites that enter the human body through
various means, then multiply, and interfere with normal vital activities.
Bacterial Diseases
● 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
○ Confirmatory test − Widal test
● Pneumonia
○ Pathogens −
Streptococcus pneumoniae
and
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
Viral Diseases
● 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
Protozoan Diseases
● Malaria
○ Pathogen −
Plasmodium
sps. (
P.vivax, P. falciparum, P. malaria
)
○ Vector − Female
Anopheles
mosquito
○ Symptoms − High grade fever, chills
● Amoebiasis
○ Pathogen −
Entamoeba histolytica
○ Vector − Housefly
○ Site of infection − Large intestine
○ Symptoms − Constipation, abdominal pain, cramps, stools with
mucous, and blood clots
Fungal Diseases
● Ringworms
○ Pathogens − Genera
Microsporum
,
Trichophyton
, and
Epidermophyton
○ Spreads through − Towels, clothes, comb (Fungus is acquired
from soil)
