Health and disease in human communities are very complex issues and have
interconnected cause. Cells are made of various chemical substance like
protein, carbohydrates, fats or lipids. Although it looks static but it is
a very dynamic system. Cells move from place to place or being in a same
place they repair or create new cells and perform various activities in our
body. The heart is pumping blood, the lungs for breathing, the kidney is
filtering the urine and the brain is thinking. All these activities are
interconnected and if one of the organs fails then the whole system will
fall into trouble. Anything that prevents proper functioning of cells and
tissues will lead to lack of proper activity of body and is termed as
disease or illness.
Significance of health
Health is the state of being well enough to function well physically,
mentally and socially. Being healthy differs from person to person.
Personal and community issues both matter for health
Healthy cannot be something that each one of us can achieve entirely on our
own. All organism will depend on their surroundings or their environment
for good health. The environment includes the physical environment. Human
beings live in society so social environment also plays an important factor
in our individual health. For example, in a society there are garbage
agencies who takes care of collecting all the garbage and disposed them
into a particular place.
The opportunity to do work has to be available because by doing work we can
earn and have food to maintain our health.
Distinction between disease free and healthy
Disease can be explained as the disturbed ease. It can be a specific and
particular cause of discomfort. Seeing a disease, we cannot know the
absolute final cause for causing the disease.
On the other hand, a man can be in a poor health without suffering from any
particular disease. So, diseased is not the same as being healthy. Like
good health for a dancer would be the ability to stretch his body into
different graceful position, the good health of a musician means enough
breathing capacity to control the notes of his flute.
Disease and its cause
What does disease look like?
When there is a disease in a person that means the functioning or the
appearance of one or more system of the body will change for the worse.
These changes give rise to symptoms and signs of disease. Each of the organ
systems have specific organs as its part and has it particular functions.
So, when a disease is caused the functioning of a particular organ system
is disturbed.
Signs of disease are what doctors will look for on the basis of their
symptoms. It gives a little more indication of the presence of a particular
disease.
Acute and chronic disease
Some disease last only for very short period of time and are called as
acute diseases. Common cold dysentery are some examples of acute diseases.
Some diseases last for long time even as much as a lifetime and are called
as chronic diseases. Diabetes, elephantiasis are some example of chronic
diseases.
Chronic diseases and poor health
Any disease that cause poor functioning of some part of the body will
affect our general health as well because all functions of our body are
necessary for general health. An acute disease does not have major effect
on our general health but a chronic disease will have.
For example, on common cold we do not lose weight or become short of breath
or not feel tired all the time. But in case of tuberculosis a chronic
disease of lungs we fall ill many times a year, ultimately lose weight and
feel tired all the time.
Cause of disease
Cause of disease are of many levels.
The first level for the cause of a disease is the attack of virus that can
cause loose motion, common cold, etc.
The second level of the cause of disease is the lack of good nourishment
and also because of not getting enough food.
Poverty or lack of public services become the third level for the cause of
a diseases.
All diseases will have immediate cause and also contributory cause. Most of
the diseases will have many cause rather than only one single cause.
Infectious and noninfectious cause
The immediate cause a disease belongs to two distinct types
One group of cause is the infectious agents, mostly
microbes or microorganisms. Disease where microbes are the immediate cause
are called infectious diseases. This is because the microbes can spread in
the community and the cause will also spread with them.
Other group of diseases are those not caused by the infectious agents.
Their cause varies, they have no external causes like microbes that can
spread in community, these are mostly internal noninfectious cause. Cancers
are caused by genetic abnormality and is a example of noninfectious cause.
Infectious diseases
Infectious agent
Organisms that can cause disease are found in wide range of categories of
classification. Some of them are virus, bacteria, fungi and other
single-celled animals or protozoans.
Common example of diseases caused by virus are common cold, influenza,
dengue fever and aids.
Common skin infections are caused by different kind of fungi. All human
have some common intestinal worm infection as well as disease like
elephantiasis caused by different species of worms.
We take antibiotics which commonly block biochemical path important for
bacterial growth. The antibiotic penicillin blocks the bacterial process
that build the cell wall. As a result the growing bacteria become unable to
make cell wall and die easily.
Means of spread of disease
Many microbial agents can commonly move from an infected person to someone
else in a variety of way. Disease caused by them are called communicable diseases which can be communicated from one
person to another.
Diseases can be caused by microbes spreading through air.
Disease can also be spread through water. This occurs if the excreta from
an infectious gut disease such as cholera get mixed with the drinking water
used by people living nearby.
Sexual act is one of the closest physical contact two people can have with
each other and microbial diseases such as syphilis or AIDS can be
transmitted through sexual contact from one partner to the other.
Organ specific and tissue specific manifestations
Different species of microbes seem to have evolved to home in on different
parts of the body. This selection is connected to their point of entry. If
they enter from the air via the nose they most likely go to the lungs. This
is seen in the bacteria causing tuberculosis.
But this need not always be the case. In infection like HIV that comes into
the body by the sexual organ spread through all over the body.
Malaria causing microbes entering through a mosquito bite will go to the
liver and then to the red blood cells. The virus causing Japanese
encephalitis or brain fever will similarly enter through mosquito bite but
it goes on to infect the brain.
The signs and symptoms of a disease will thus depend on the tissue or organ
which the microbe targets. When the lungs are targeted then the symptoms
will differ from that when the liver is targeted.
In some special case the tissue specificity of the infection leads to very
general seeming effects. For example, in HIV infection the virus caused
weakening of the immune system and damages its function and can cause
multiple symptoms.
Principle of treatment
Treatment can be of two types, one that would be to reduce the effect of
the disease and the other is to kill the cause of the disease. In case of
loose motion, we must take bed rest to conserve energy so that we can heal
your body. But in this way of the symptoms directed treatment the infecting
microbes will not go away and the disease will not be cured. The way to
kill those microbes is to use medicine so that the disease can be cured.
Each of the groups of microorganism has some essential biochemical life
process which is peculiar to that group and not shared with other group.
These processes may be the pathway for the synthesis of new substance or
respiration. To stop this process of pathway we find a particular drug that
blocks the pathway without affecting our body and these drugs are called as
antibiotics.
Principle of prevention
Prevention of disease is more desirable than its successful treatment.
Effective prevention of infectious disease in the community requires that
everyone should have access to public hygiene and immunization. Infectious
diseases can be prevented by public health hygiene measure that reduces
exposure to infectious agent. Infectious diseases can be prevented by using
proper immunization.