Factors affecting human
health can be divided into two categories:
health can be divided into two categories:
i.
Intrinsic
or internal factors
ii.
Extrinsic
or external factors
I. Intrinsic factors
Disease-causing factors
found within the human body are called intrinsic factors. They are:
found within the human body are called intrinsic factors. They are:
Ø
Malfunctioning
of body parts: Many diseases are caused
due to improper functioning of body organs. For example, cardiac failure (heart
attack) is caused by improper functioning of heart and short-sightedness, long-sightedness
and cataract are caused due to improper functioning of eye.
Malfunctioning
of body parts: Many diseases are caused
due to improper functioning of body organs. For example, cardiac failure (heart
attack) is caused by improper functioning of heart and short-sightedness, long-sightedness
and cataract are caused due to improper functioning of eye.
Ø
Hereditary
diseases: Diseases, which are passed
on from generation to generation, are called hereditary diseases. Haemophilia,
a rare disease in which the patient’s blood doesn’t clot easily and sickle cell
anaemia, a disease in which the patient’s red blood cells become sickle-shaped
due to the presence of defective haemoglobin are hereditary diseases.
Hereditary
diseases: Diseases, which are passed
on from generation to generation, are called hereditary diseases. Haemophilia,
a rare disease in which the patient’s blood doesn’t clot easily and sickle cell
anaemia, a disease in which the patient’s red blood cells become sickle-shaped
due to the presence of defective haemoglobin are hereditary diseases.
Ø
Hormonal
diseases: Hormones control most of
our body functions. A defect in the production or action of hormones can cause
hormonal diseases. Diabetes is a disease caused due to the underproduction of
insulin hormone by pancreas. Overproduction of growth hormone (GH) produced by
pituitary leads to development of giants while its underproduction leads to
development of dwarfs.
Hormonal
diseases: Hormones control most of
our body functions. A defect in the production or action of hormones can cause
hormonal diseases. Diabetes is a disease caused due to the underproduction of
insulin hormone by pancreas. Overproduction of growth hormone (GH) produced by
pituitary leads to development of giants while its underproduction leads to
development of dwarfs.
Ø
Allergy: Some people are sensitive to dust, pollen, certain
drugs and foodstuffs and develop rashes on the skin or begin to sneeze. This
type of hypersensitivity to certain substances is called allergy and can be prevented
by avoiding contact with the allergy causing substance.
Allergy: Some people are sensitive to dust, pollen, certain
drugs and foodstuffs and develop rashes on the skin or begin to sneeze. This
type of hypersensitivity to certain substances is called allergy and can be prevented
by avoiding contact with the allergy causing substance.
II. Extrinsic factors:
Disease causing factors
coming from outside the human body are called extrinsic factors. They are:
coming from outside the human body are called extrinsic factors. They are:
Ø Nutritional disorders: Diseases caused by deficiency or excess of essential
nutrients in diet are called nutritional disorders. Deficiency diseases like
kwashiorkor, scurvy, rickets, goitre, anaemia, etc., are caused due to
deficiency of essential nutrients in the body.
nutrients in diet are called nutritional disorders. Deficiency diseases like
kwashiorkor, scurvy, rickets, goitre, anaemia, etc., are caused due to
deficiency of essential nutrients in the body.
Ø Infection by microorganisms: Micro-organisms (bacteria, viruses, fungi and
protozoa) enter the human body through contaminated food, water and air,
through skin contact and insect-bites.
protozoa) enter the human body through contaminated food, water and air,
through skin contact and insect-bites.
Ø Habit forming substances: Substances like alcohol, tobacco and narcotic drugs
tend to make a person increasingly dependent on them. Hence, they are called
habit-forming substances. Excessive intake of tobacco, cigarette or cigar and
direct chewing can lead to accumulation of tar in the nose, throat and lungs
causing cough and irritation. Tobacco smokers also run a higher risk of heart
attack. Alcohol is consumed in the form of wine, whiskey, beer, gin, etc.
Alcohol affects the nervous system. It reduces the alertness of mind. It
increases the time a person normally takes to respond or react to an emergency.
(This time is called reaction time.) Excessive intake of alcohol can damage the
liver. Opium and heroin are narcotic drugs. They are highly addictive and it is
highly difficult to give them up. Narcotic drugs damage the nervous system and
adversely affect vision, hearing respiratory system and heart. Excessive intake
of narcotics may lead to heath.
tend to make a person increasingly dependent on them. Hence, they are called
habit-forming substances. Excessive intake of tobacco, cigarette or cigar and
direct chewing can lead to accumulation of tar in the nose, throat and lungs
causing cough and irritation. Tobacco smokers also run a higher risk of heart
attack. Alcohol is consumed in the form of wine, whiskey, beer, gin, etc.
Alcohol affects the nervous system. It reduces the alertness of mind. It
increases the time a person normally takes to respond or react to an emergency.
(This time is called reaction time.) Excessive intake of alcohol can damage the
liver. Opium and heroin are narcotic drugs. They are highly addictive and it is
highly difficult to give them up. Narcotic drugs damage the nervous system and
adversely affect vision, hearing respiratory system and heart. Excessive intake
of narcotics may lead to heath.
Ø Environmental pollution: Dust, pollen, carbon monoxide, carbon dioxide, sulphur
dioxide and nitrogen oxides pollute the environment. They cause headache,
cough, allergies, lung disorders and bronchitis. Pesticides and chemical wastes
from industries can cause damage to human health.
dioxide and nitrogen oxides pollute the environment. They cause headache,
cough, allergies, lung disorders and bronchitis. Pesticides and chemical wastes
from industries can cause damage to human health.