HUMAN HEALTH AND

DISEASES

 COMMON DISEASES IN
HUMANS :

1. Fever: This disease is caused by the pathogenic

bacterium Salmonella Typhoid typhi. The
pathogens typically enter the small intestine via

contaminated food and water and then migrate to

other organs through the blood3. Common
symptoms include a sustained high fever (39° to
40°C), weakness, stomach pain, constipation,
headache, and loss of appetite3. In severe cases,
intestinal perforation and death may occur3.
Typhoid fever can be confirmed by the Widal
test3.... A classic case is Mary Mallon, nicknamed
Typhoid Mary, who was a cook and a typhoid carrier
who spread the disease for several years through
the food she prepared4.
 HUMAN HEALTH AND
DISEASES
1.Pneumonia: Bacteria such as Streptococcus
pneumoniae and Haemophilus influenzae are responsible
for pneumonia in humans5. This disease infects the alveoli
(air-filled sacs) of the lungs, causing them to fill with fluid,
which leads to severe respiratory problems5. Symptoms
include fever, chills, cough, and headache5. In severe
cases, the lips and fingernails may turn gray to bluish5.
Infection can be acquired by inhaling droplets or aerosols
released by an infected person or by sharing contaminated
items like glasses and utensils5. Other bacterial diseases
mentioned include dysentery, plague, and diphtheria5.
2.
Common Cold: Rhino viruses are a group of viruses that
cause the common cold, one of the most infectious human
ailments6. These viruses infect the nose and respiratory
passage, but specifically not the lungs6. Symptoms include
nasal congestion and discharge, sore throat, hoarseness,
cough, headache, and tiredness, usually lasting for 3-7
days6
. Malignant malaria, caused by Plasmodium falciparum, is
the most serious type and can be fatal. Plasmodium
entethe bite of an infected female Anopheles mosquito8.
 HUMAN HEALTH AND
DISEASES
The parasites initially multiply in liver cells before attacking
red blood cells (RBCs), causing them to rupture8. The
rupture of RBCs is linked to the release of a toxic substance
called haemozoin, which is responsible for the chills and
high fever that recur every three to four days8. The
malarial parasite requires two hosts, humans and
mosquitoes, to complete its life cycle, with the female
Anopheles mosquito acting as the vector.

3.
Amoebiasis (Amoebic Dysentery): Caused by
Entamoeba histolytica, a protozoan parasite found in the
large intestine of humans10. Symptoms include
constipation, abdominal pain and cramps, and stools
containing excess mucous and blood clots10. Houseflies
can act as mechanical carriers, transmitting the parasite
from the faeces of infected individuals to food and food
products, thus contaminating them10. Drinking water and
food contaminated by faecal matter are the primary
sources of infection10.
4.
Ascariasis: This disease is caused by Ascaris, the common
round worm, which is a helminth and an intestinal
parasite11. Symptoms include internal bleeding, muscular
pain, fever, anemia, and blockage of the intestinal
passage11. Infection is acquired by a healthy person
through contaminated water, vegetables, and fruits, which
become contaminated by the parasite's eggs excreted in
the faeces of infected persons11.
 HUMAN HEALTH AND
DISEASES
5. Elephantiasis (Filariasis): Caused by filarial
worms like Wuchereria (W. bancrofti and W.
malayi), this disease results in a slowly developing
chronic inflammation of the organs where the
worms live for many years, typically the lymphatic
vessels of the lower limbs12. The genital organs
are also often affected, leading to gross
deformities12. The pathogens are transmitted to a
healthy person through the bite of female mosquito
vectors12.

6. Ringworms: Fungi belonging to the genera

Microsporum, Trichophyton, and Epidermophyton
are responsible for ringworms, which are among
the most common infectious diseases in
humans13. The main symptoms are dry, scaly
lesions on various parts of the body like the skin,
nails, and scalp, accompanied by intense itching13.
These fungi thrive in heat and moisture,
particularly in skin folds13. Ringworms are
generally acquired from soil or by using
contaminated items like towels, clothes, or combs
belonging to infected individuals13.

 IMMUNITY
immunity is defined as the overall ability of
the host to fight the disease-causing organisms,
which is conferred by the immune system1. This ability
allows the body to defend itself from most infectious
agents, even when exposed to a large number of them1.
Immunity is broadly categorized into two types:
 HUMAN HEALTH AND
DISEASES
1.
Innate immunity2.
2.
Acquired immunity2.
Innate immunity is a non-specific type of defence that
is present at the time of birth2. It works by providing
different types of barriers to prevent foreign agents from
entering the body2. These barriers include:
•
Physical barriers: Skin is the main barrier preventing the
entry of micro-organisms. Mucus coating in the respiratory,
gastrointestinal, and urogenital tracts also helps trap
microbes3.
•
Physiological barriers: Acid in the stomach, saliva in the
mouth, and tears from the eyes all prevent microbial
growth3.
•
Cellular barriers: Certain white blood cells (WBCs) like
polymorpho-nuclear leukocytes (PMNL-neutrophils),
monocytes, natural killer lymphocytes in the blood, and
macrophages in tissues can engulf and destroy
microbes3....
•
Cytokine barriers: Virus-infected cells release proteins
called interferons, which protect non-infected cells from
 HUMAN HEALTH AND
DISEASES
further viral infection4.

Acquired immunity, in contrast, is pathogen specific4.

A key characteristic of acquired immunity is memory4....
When the body encounters a pathogen for the first time, it
generates a primary response, which is typically of low
intensity4. Upon subsequent exposure to the same
pathogen, a much more intense secondary or
anamnestic response is elicited4. This intensified
response is due to the body's memory of the initial
encounter4.
Acquired immune responses are carried out by two specific
types of lymphocytes in the blood: B-lymphocytes and T-
 HUMAN HEALTH AND
DISEASES
lymphocytes7.

•
B-lymphocytes produce proteins called antibodies in the
blood to fight pathogens7. Different types of antibodies
include IgA, IgM, IgE, and IgG8. Antibodies are Y-shaped
molecules consisting of four peptide chains: two light
chains and two heavy chains (represented as H₂L₂)8. The
immune response mediated by antibodies found in the
blood is called humoral immune response or antibody
mediated acquired immune response8.
•
T-lymphocytes do not secrete antibodies themselves but
help B cells produce them7. T-lymphocytes also mediate
the cell-mediated immune response (CMI)9. The ability
of the body to differentiate 'self' and 'nonself' is mediated
by CMI, and it is responsible for the rejection of organ
 HUMAN HEALTH AND
DISEASES
grafts during transplantation10.... Tissue and blood group
matching are essential before transplantation, and even
then, immunosuppressants are often needed life-long to
prevent rejection10.
Immunity can also be described based on how it is
acquired:
•
Active immunity: Occurs when a host is exposed to
antigens (which can be living or dead microbes or other
proteins), and the host's body produces antibodies in
response12. This type of immunity is slow and takes time
to become fully effective12. It can be induced deliberately

during immunisation (vaccination) or through natural

infection12.
•
Passive immunity: Occurs when ready-made antibodies
are directly given to protect the body against foreign
agents12. Examples include the transfer of abundant
 HUMAN HEALTH AND
DISEASES
antibodies (IgA) from mother's colostrum to a newborn
infant and the transfer of some antibodies from the mother
to the foetus through the placenta during pregnancy5.... In
cases requiring a quick immune response against deadly
microbes (like tetanus) or snakebites, preformed antibodies
or antitoxin are injected, which is also a type of passive
immunisation13.
The principle of immunisation or vaccination is based
on the immune system's property of memory5.... In
vaccination, a preparation containing antigenic proteins of
a pathogen or an inactivated/weakened pathogen (vaccine)
is introduced into the body5. The antibodies produced
neutralise the pathogens during actual infection5....
Vaccines also generate memory B and T-cells that can
quickly recognise and respond to the pathogen upon
subsequent exposure with a massive production of
antibodies13. Advancements like recombinant DNA
technology have enabled large-scale production of newer
and safer vaccines, such as the hepatitis B vaccine
produced from yeast14.
Beyond fighting pathogens, the immune system plays an
important role in other reactions, including allergic
reactions, auto-immune diseases, and organ
transplantation11.
•
Allergy is an exaggerated response of the immune system
to certain environmental antigens called allergens15....
Antibodies of the IgE type are produced in response to
allergens16.
 HUMAN HEALTH AND
DISEASES

•
Auto-immune diseases occur sometimes, due to genetic
or unknown reasons, when the body attacks its own cells,
damaging the body17. Rheumatoid arthritis is an example
of an auto-immune disease17.
The human immune system itself is composed of lymphoid
organs, tissues, cells, and soluble molecules like
antibodies11. Lymphoid organs are where lymphocytes
originate, mature, and multiply18. Primary lymphoid organs
(bone marrow and thymus) are where immature
lymphocytes become antigen-sensitive18. Secondary
lymphoid organs (spleen, lymph nodes, tonsils, Peyer’s
patches, appendix) provide sites for lymphocytes to
interact with antigens and become effector cells18....
Lymphoid tissue is also found associated with the lining of
major tracts (respiratory, digestive, urogenital) and is
called mucosa-associated lymphoid tissue (MALT), making
up about 50 per cent of the body's lymphoid tissue20.
 HUMAN HEALTH AND
DISEASES
Finally, AIDS (Acquired Immuno Deficiency Syndrome)
represents a deficiency of the immune system acquired
during a person's lifetime21. It is caused by the Human
Immuno deficiency Virus (HIV), which attacks helper T-
lymphocytes, leading to a progressive decrease in their
number and severely impairing the immune system's
ability to fight infections6....

 Vaccination and
Immunisation
Vaccination and Immunisation is a crucial
public health measure based on the principles of the
immune system1....
The principle of immunisation or vaccination is founded
on the immune system's property of memory1. During
vaccination, a preparation containing antigenic proteins
of a pathogen or an inactivated/weakened pathogen
(which is called a vaccine) is introduced into the body1.
Here's how it works according to the sources:
•
The body produces antibodies against these introduced
antigens1.
•
These antibodies would then neutralise the
pathogenic agents if a real infection occurs1.
•
Crucially, vaccines also generate memory B
and T-cells1. These memory cells are designed
 HUMAN HEALTH AND
DISEASES

to quickly recognise the pathogen upon

subsequent exposure1.

When the body encounters the actual pathogen

again, the memory cells elicit a massive
production of antibodies, overwhelming the
invaders1. This is an example of the immune
system's intensified secondary or anamnestic
response4.
In certain situations where a quick immune
response is needed against deadly microbes,
such as in tetanus or snakebites, preformed
antibodies or antitoxin (a preparation
containing antibodies) are directly injected1.
This is a type of immunisation called passive
immunisation1.
Advancements like recombinant DNA
technology have enabled the production of
antigenic polypeptides of pathogens in
organisms like bacteria or yeast5. This has led
to the large-scale production of newer and
safer vaccines, increasing their availability for
immunisation5. The hepatitis B vaccine
produced from yeast is given as an example5.
Vaccines and immunisation programmes have
had a significant impact on human health6.
 HUMAN HEALTH AND
DISEASES

They have allowed for the complete eradication

of diseases like smallpox6. Furthermore, a large
number of other infectious diseases, including
polio, diphtheria, pneumonia, and tetanus,
have been controlled to a great extent through
the use of vaccines6. Immunisation is also
considered necessary for achieving good
health2.

 Allergies
Allergy is defined as the exaggerated
response of the immune system to
certain antigens present in the
environment1.
Here are the key details about allergies from
the sources:
•
The substances that cause this exaggerated
immune response are called allergens1.
•
 HUMAN HEALTH AND
DISEASES

Common examples of allergens mentioned

are mites in dust, pollens, and animal

dander1.
•
In response to allergens, the immune system
produces specific antibodies of the IgE
type1.
•
The symptoms of allergic reactions can
include sneezing, watery eyes, running nose,
and difficulty in breathing1.
•
These symptoms are due to the release of
chemicals such as histamine and
serotonin from mast cells1.
•
 HUMAN HEALTH AND
DISEASES

To determine the cause of an allergy, a

patient may be exposed to or injected with
very small doses of possible allergens, and
the resulting reactions are studied1.
•
Drugs like anti-histamines, adrenalin, and
steroids can quickly reduce the symptoms of
allergy1.
•
The sources note that modern-day lifestyle
might lead to a lowering of immunity and
increased sensitivity to allergens2. It is
observed that more children in metro cities in
India suffer from allergies and asthma due to
sensitivity to the environment, which could
potentially be a result of the protected
environment provided early in life2.
•
The immune system plays an important role
in allergic reactions

 Auto Immunity
auto-immunity occurs sometimes, due to
genetic and other unknown reasons, when the
body's immune system attacks its own cells1. This
attack results in damage to the body1.
The ability of the immune system to differentiate 'self'
from 'nonself' is the basis for memory-based acquired
immunity1.... However, in auto-immune diseases, this
 HUMAN HEALTH AND
DISEASES
differentiation process fails, leading the body to attack
its own components1.
Rheumatoid arthritis is provided as an example of
an auto-immune disease1.
The immune system plays an important role
in auto-immune diseases

 AIDS
It is described as a deficiency of the
immune system that is acquired during
the lifetime of an individual1. This means it
is not a congenital disease (present at
birth)1. The term 'Syndrome' indicates that it
is a group of symptoms1.
AIDS is caused by the Human Immuno
deficiency Virus (HIV)2.... HIV is a member
of a group of viruses called retrovirus, which
 HUMAN HEALTH AND
DISEASES

have an envelope enclosing an RNA genome

Here's how the virus impacts the body's

immune system:
•
After entering the body, the virus enters into
macrophages, where its RNA genome
replicates to form viral DNA4.
•
This viral DNA incorporates into the host
cell's DNA, directing the infected cell to
produce more virus particles4. Macrophages
act like an "HIV factory"4.
•
 HUMAN HEALTH AND
DISEASES

Simultaneously, HIV enters into helper T-

lymphocytes (T H), replicates, and produces
progeny viruses4.
•
The progeny viruses released into the blood
then attack other helper T-lymphocytes4.
This process repeats, leading to a
progressive decrease in the number of
helper T-lymphocytes in the infected
person's body4.
•
Helper T-lymphocytes are crucial for the
immune system4. Due to their decrease, the
person becomes immuno-deficient5.
•
This immuno-deficiency makes the person
unable to protect themselves against various
infections they could otherwise overcome,
such as those caused by bacteria (especially
Mycobacterium), viruses, fungi, and even
parasites like Toxoplasma5.
Common symptoms include bouts of fever,
diarrhoea, and weight loss4, in addition to
the opportunistic infections resulting from the
weakened immune system5.
Transmission of HIV infection generally occurs
through2...:
•
 HUMAN HEALTH AND
DISEASES

Sexual contact with an infected person2....

•
Transfusion of contaminated blood and blood
products2....
•
Sharing infected needles, common among
intravenous drug abusers2....
•
From an infected mother to her child, either
through the placenta during pregnancy or via
other means (like milk, though the source
specifically mentions placenta transfer during
pregnancy)2....
Individuals at high risk include those with
multiple sexual partners, drug addicts who
inject intravenously, people requiring
repeated blood transfusions, and children
born to HIV-infected mothers8. It's important
to note that HIV/AIDS is not spread by
mere touch or physical contact; it spreads
only through body fluids8.
There can be a significant time-lag between
getting infected and the appearance of AIDS
symptoms, ranging from a few months to
many years, typically 5-10 years9.
A widely used diagnostic test for AIDS is
ELISA (enzyme linked immuno-sorbent
assay)5.
 HUMAN HEALTH AND
DISEASES

Currently, treatment for AIDS with anti-

retroviral drugs is only partially effective;
while they can prolong the patient's life, they
cannot prevent the inevitable death5.
Given that there is no cure, prevention is
considered the best option7.

Prevention measures include ensuring blood

safety10, using only disposable needles and
syringes10, advocating safe sex, controlling
drug abuse, and promoting regular check-ups
for HIV in susceptible populations10.
Education and guidance are also highlighted
as crucial for prevention, especially among
youth7....
The sources also mention that AIDS is a
deadly disease3... and a major cause of
death worldwide3. One source lists it under
 HUMAN HEALTH AND
DISEASES

infectious diseases12, while another

mentions it as a fatal non-infectious
disease13, but the detailed description
clearly indicates it is caused by an infectious
agent (virus) and is transmissible.
People infected with HIV/AIDS should not be
isolated but require help and sympathy from
society8.... Tackling the spread requires
collective societal and medical effort14.

 CANCER
Cancer is described as one of the most
dreaded diseases of human beings and a
major cause of death all over the globe1.
In India, more than a million people suffer
from cancer, and a large number die
annually.
 HUMAN HEALTH AND
DISEASES

Opioids: These bind to specific opioid receptors in the

central nervous system and gastrointestinal tract5. Heroin
(smack) is a common opioid, chemically diacetylmorphine,
obtained from the poppy plant Papaver somniferum5. It is a
depressant, slowing down body functions5.
◦
Cannabinoids: These interact with cannabinoid receptors
mainly in the brain6. Natural cannabinoids come from the
Cannabis sativa plant; its parts are used to produce
marijuana, hashish, charas, and ganja6. These are known
for their effects on the cardiovascular system.
 HUMAN HEALTH AND
DISEASES

◦
Coca Alkaloids: Cocaine (coke or crack) is obtained from the coca plant
Erythroxylum coca7. It interferes with the transport of dopamine and acts as a
potent stimulant on the central nervous system, causing euphoria and increased
energy7. Excessive doses can cause hallucinations7.
◦
Other drugs: Barbiturates, amphetamines, and benzodiazepines, normally used
as medicines for mental illnesses like depression and insomnia, are also often
abused8. Morphine is a strong sedative and painkiller often used after surgery8.
◦
Tobacco: Tobacco contains nicotine, which stimulates the adrenal gland to
release adrenaline and nor-adrenaline, increasing blood pressure and heart
rate9. Tobacco use is associated with various cancers (lung, urinary bladder,
throat, oral cavity), bronchitis, emphysema, coronary heart disease, and gastric
ulcer, and it reduces oxygen in the blood9. Smoking can also lead to the use of
harder drugs9.
•
Addiction and Dependence: Repeated use of drugs is driven by their perceived
benefits and their inherent addictive nature13.
◦
 HUMAN HEALTH AND
DISEASES
Addiction is a psychological attachment to effects like euphoria and temporary
well-being, causing continued use even when not needed or when self-
Harmful Effects:
◦
Immediate effects include reckless behaviour, vandalism, and violence3.
◦
Excessive doses can lead to coma and death from respiratory failure, heart
failure, or cerebral hemorrhage, especially when combining drugs or mixing
them with alcohol3.
◦
Warning signs in youth include a drop in academics, unexplained absence from
school, poor hygiene, withdrawal, isolation, depression, fatigue, aggressive
behaviour, deteriorating relationships, loss of interest in hobbies, and changes in
sleeping/eating habits and weight16.

Use during pregnancy can harm the fetus18.

◦
Misuse by sportspersons (anabolic steroids, etc.) can lead to severe side effects
such as masculinisation, aggressiveness, mood swings, depression, abnormal
menstrual cycles, hair growth, voice deepening, and clitoris enlargement in
females; acne, aggressiveness, mood swings, depression, reduced testicle size,
decreased sperm production, kidney/liver dysfunction, breast enlargement,
baldness, and prostate enlargement in males19.... In adolescents, it can also cause
severe acne and stunted growth20.
•
Prevention and Control: Prevention is the best approach, especially during
adolescence21. Parents and teachers have a special responsibility21. Measures
include:
◦

Opioids: These bind to specific opioid

receptors in the central nervous system and
gastrointestinal tract5. Heroin (smack) is a
common opioid, chemically
diacetylmorphine, obtained from the poppy
plant Papaver somniferum5. It is a
depressant, slowing down body functions5.
◦
 HUMAN HEALTH AND
DISEASES

Cannabinoids: These interact with

cannabinoid receptors mainly in the brain6.
Natural cannabinoids come from the
Cannabis sativa plant; its parts are used to
produce marijuana, hashish, charas, and
ganja6. These are known for their effects on
the cardiovascular system6.
◦
Coca Alkaloids: Cocaine (coke or crack) is
obtained from the coca plant Erythroxylum
coca7. It interferes with the transport of
dopamine and acts as a potent stimulant on
the central nervous system, causing euphoria
and increased energy7. Excessive doses can
cause hallucinations7.
◦
Other drugs: Barbiturates, amphetamines,
and benzodiazepines, normally used as
medicines for mental illnesses like depression
and insomnia, are also often abused8.
Morphine is a strong sedative and painkiller
often used after surgery8.
◦
Tobacco: Tobacco contains nicotine, which
stimulates the adrenal gland to release
adrenaline and nor-adrenaline, increasing
blood pressure and heart rate9. Tobacco use
is associated with various cancers (lung,
 HUMAN HEALTH AND
DISEASES

urinary bladder, throat, oral cavity),

bronchitis, emphysema, coronary heart
disease, and gastric ulcer, and it reduces
oxygen in the blood9. Smoking can also lead
to the use of harder drugs9.

Addiction is a psychological attachment to

effects like euphoria and temporary well-
being, causing continued use even when not
needed or when self-destructive13. With
repeated use, the body's tolerance increases,
requiring higher doses, leading to greater
intake and addiction14. Even a single use can
be a precursor to addiction14. This creates a
vicious circle14.
◦
Harmful Effects:
◦
Immediate effects include reckless
behaviour, vandalism, and violence3.
◦
Excessive doses can lead to coma and death
from respiratory failure, heart failure, or
cerebral hemorrhage, especially when
combining drugs or mixing them with
alcohol3.
•
 HUMAN HEALTH AND
DISEASES

Prevention and Control: Prevention is the

best approach, especially during
adolescence21. Parents and teachers have a
special responsibility21. Measures include:
◦
Education and counselling to help cope with
stress and channel energy into healthy
activities like sports, reading, music, and
yoga.
◦
Seeking help from parents, peers, or trusted
friends.
◦
Alert parents and teachers looking for danger
signs.
◦
Seeking professional and medical help from
psychologists, psychiatrists, and de-
addiction/rehabilitation programs.

Coca Alkaloids: Cocaine (coke or crack) is

obtained from the coca plant Erythroxylum
coca. It interferes with the transport of
dopamine and acts as a potent stimulant on
the central nervous system, causing euphoria
and increased energy. Excessive doses can
cause hallucinations.
 HUMAN HEALTH AND
DISEASES

Other drugs: Barbiturates, amphetamines,

and benzodiazepines, normally used as
medicines for mental illnesses like depression
◦

Tobacco: Tobacco contains nicotine, which

stimulates the adrenal gland to release
adrenaline and nor-adrenaline, increasing
blood pressure and heart rate. Tobacco use is
associated with various cancers (lung,
urinary bladder, throat, oral cavity),
bronchitis, emphysema, coronary heart
disease, and gastric ulcer, and it reduces
oxygen in the blood. Smoking can also lead
to the use of harder drugs.

addiction. Even a single use can be a

precursor to addiction. This creates a vicious
circle.
◦
 HUMAN HEALTH AND
DISEASES

Dependence is the body's tendency to

manifest unpleasant withdrawal symptoms
if regular use is abruptly stopped15. These
symptoms include anxiety, shakiness,
nausea, and sweating, and can be severe,
even life-threatening, requiring medical
supervision15. Dependence can lead
individuals to disregard social norms to
obtain the substance, causing social
adjustment problems15.
•
Other drugs: Barbiturates, amphetamines,
and benzodiazepines, normally used as
medicines for mental illnesses like depression
and insomnia, are also often abused8.
Morphine is a strong sedative and painkiller
often used after surgery8.
 HUMAN HEALTH AND
DISEASES

Tobacco: Tobacco contains nicotine, which

stimulates the adrenal gland to release
adrenaline and nor-adrenaline, increasing

blood pressure and heart rate9. Tobacc o use

is associated with various cancers (lung,
urinary bladder, throat, oral cavity
•
Adolescence and Initiation: Adolescence
(12-18 years) is a vulnerable phase for
mental and psychological development10.
Curiosity, the need for adventure and
excitement, experimentation, escaping
problems, and stress (academic/examination
 HUMAN HEALTH AND
DISEASES

pressures) are common motivations for

youngsters to start using drugs or alcohol11.
•
Addiction and Dependence: Repeated use
of drugs is driven by their perceived benefits
and their inherent addictive nature13.
◦
Addiction is a psychological attachment to
effects like euphoria and temporary well-
being, causing continued use even when not
needed or when self-destructive1.
◦
Dependence is the body's tendency to
manifest unpleasant withdrawal symptoms
if regular use is abruptly stopped15. These
symptoms include anxiety, shakiness,
nausea, and sweating, and can be severe,
even life-threatening, requiring medical
supervision1.
•
Harmful Effects:
◦
Immediate effects include reckless
behaviour, vandalism, and
violence3.Excessive doses can lead to coma
and death from respiratory failure, heart
failure, or cerebral hemorrhage, especially
 HUMAN HEALTH AND
DISEASES

when combining drugs or mixing them with

alcohol3.
◦
Prevention and Control: Prevention is the
best approach, especially during
adolescence21. Parents and teachers have a
special responsibility21. Measures include:
•
Causes of Cancer: The transformation of
normal cells into cancerous cells can be
induced by physical, chemical, or biological
agents, which are called carcinogens4.
◦
Physical agents: Ionising radiations like X-
rays and gamma rays, and non-ionising
radiations like UV, can cause DNA damage
leading to transformation4.
◦
Chemical agents: Chemical carcinogens
found in tobacco smoke are identified as a
major cause of lung cancer4.
Biological agents: Cancer-causing viruses,
known as oncogenic viruses, possess
genes called viral oncogenes.
•
Detection and Diagnosis: Early detection
is considered essential for successful
treatment5. Methods include:
 HUMAN HEALTH AND
DISEASES

◦
Biopsy and histopathological studies: A
piece of suspected tissue is cut, stained, and
examined under a microscope by a
pathologist5.
◦
Blood and bone marrow tests: Used for
detecting increased cell counts, particularly
in the case of leukemias.
◦
Imaging techniques: Radiography (using X-
rays), CT (Computed Tomography - uses X-
rays for 3D images), and MRI (Magnetic
Resonance

 Drugs and alcohol abuse

Drugs and Alcohol Abuse involves the

use of certain substances that negatively
affect human health and well-being1.... It is
described as a cause of concern, particularly
among youth, and education and guidance
are suggested to help youngsters avoid these
 HUMAN HEALTH AND
DISEASES

patterns.

Opioids: These bind to specific opioid

receptors in the central nervous system and
gastrointestinal tract5. Heroin (smack) is a
common opioid, chemically
diacetylmorphine, obtained from the poppy
plant Papaver somniferum5. It is a
depressant, slowing down body functions5.
◦
Cannabinoids: These interact with
cannabinoid receptors mainly in the brain6.
Natural cannabinoids come from the
Cannabis sativa plant; parts are used to
produce marijuana, hashish, charas, and
ganja6. These are known for their effects on
the cardiovascular system6.
◦
Coca Alkaloids: Cocaine (coke or crack) is
obtained from the coca plant Erythroxylum
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DISEASES

coca7. It interferes with the transport of

dopamine and acts as a potent stimulant on
the central nervous system, causing euphoria
and increased energy. Excessive doses can
cause hallucinations.
◦
Other drugs: Barbiturates, amphetamines,
and benzodiazepines, normally used as
medicines for mental illnesses like depression
and insomnia, are also often abused.
Morphine is a strong sedative and painkiller
often used after surgery.

◦
Tobacco: Tobacco contains nicotine, which
stimulates the adrenal gland to release
adrenaline and nor-adrenaline, increasing
blood pressure and heart rate. Tobacco use is
associated with various cancers (lung,
urinary bladder, throat, oral cavity),
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DISEASES

bronchitis, emphysema, coronary heart

disease, and gastric ulcer, and it reduces
oxygen in the blood9. Smoking can also lead
to the use of harder drugs.
•
Addiction and Dependence: Repeated use
of drugs is driven by their perceived benefits
and their inherent addictive nature.
◦
Dependence is the body's tendency to
manifest unpleasant withdrawal symptoms
if regular use is abruptly stopped. These
symptoms include anxiety, shakiness,
nausea, and sweating, and can be severe,
even life-threatening, requiring medical
supervision. Dependence can lead individuals
to disregard social norms to obtain the
substance, causing social adjustment
problems15.
•
Harmful Effects:
◦
Immediate effects include reckless
behaviour, vandalism, and violence3.
◦
Excessive doses can lead to coma and death
from respiratory failure, heart failure, or
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DISEASES

cerebral hemorrhage, especially when

combining drugs or mixing them with alcohol.
◦
Long-term effects include potential stealing
to fund the habit1, and causing mental and
financial distress to family and friends.
◦
Intravenous drug use by sharing needles
significantly increases the risk of serious and
potentially fatal infections like AIDS and
Hepatitis B18.
◦
•
Prevention and Control: Prevention is the
best approach, especially during
adolescence. Parents and teachers have a
special responsibility. Measures include:
◦
Avoiding undue peer pressure and respecting
individual choices.

◦
Education and
counselling to help
cope with stress and
channel energy into
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DISEASES

healthy activities like sports, reading, music,

and yoga.