Intro to Diseases1

8/2/2019 Intro to Diseases1

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Introduction to Human

DiseasesChapter 1: Introduction to HumanDiseases. Neighbors and Tannehill-Jones

Pete LeRoy, PhD

Department of Exercise and Sport Studies

New Mexico Highlands University


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A Few Learning

Objectives1. Define Basic Terminologyused in the study of Human

Diseases2. Discuss the Pathogenesisof Disease3. Describe the Standard PrecautionGuidelinesfor Disease

Prevention4. Identify Predisposing Factorsto Human Disease5. Explain the differences between Diagnosisand Prognosisof a

Disease.6. Differentiate between Infectious Diseasesand Chronic

Diseases7. Discuss the role ofMedicineand the role ofEducationas

they pertain to disease8. Explain why the Infectious Diseasesno longer pose the

major challenge and why they have been replaced byChronic Diseases


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Overview

The study of Human Diseases is important so thatwe can better prevent and treatdiseases. It isalways better to preventa disease, when possible,

then to wait for the disease to occur and have todepend upon treatment. Some diseases affect onlyone part of the body or a particular body system,whereas other diseases affect several body parts orbody systems at the same time. There are many

factors that influence the bodys ability to remainhealthy or predispose it to the diseases process.Many of these factors are controllablewhile someare non-controllable(heredity).


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Some of the Termswe will Examine

Disease

Disorder

SyndromeHomeostasis

Pathology

Pathogens

PathogenesisEtiology

Acute

Chronic

Idiopathic

Iatrogenesis

NosocomialDiagnosis

Prognosis

Palliative

RemissionExacerbation

Morbidity

Mortality


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Disease & Disorder

These terms are often used synonymously. Diseaseis a change in in structure or function considered tobe abnormal (unhealthy). A disease state meansthere is pathology (structural & functional changesin tissue and organs). In a disease state,homeostasis (the bodys maintenance of normalcy)is disrupted.

Disorder is defined as a derangement of functionnot related to pathology. A nutritional disorder, for

example might be related to a vitamin deficiency. In practice, the terms are often used

interchangeably.


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Pathology

Broadly defined, the word pathologymeans the study of disease.

(patho=disease, ology=study). Moreprecisely defined, it means thatbranch of medicine which treats of theessential nature of disease, especially

the structural and functional changesin tissues and organs of the bodycaused by disease.


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Pathologists

A pathologist is one who studies disease. Thereare different types of pathologists:

1. Experimental research

2. Academic teaching

3. Anatomic clinical examinations (autopsies,biopsies)

4. Clinical laboratory examinations (hematology,

immunology, microbiology) Pathogenesis is a description of how a disease

progresses. For example, the common cold.


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Pathogens

Pathogens are microorganismsthat causedisease. Pathogens can be:

1. Bacteriasingle-celled microscopic organisms

2. Virusesinfectious agents much smaller thanbacteria. They can only replicate within a livinghost cell.

3. Fungimicroscopic plant-like organisms (yeastand molds)

4. Protozoanssingle-celled microscopic parasites5. Helminthes - worms Pathogens produce a structural and functional

change in tissue and organs.


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Etiology & Idiopathic

The cause of a disease is the etiology of thea disease. For example, the primary

etiology of lung cancer is cigarette smoking.When the etiology is unknown, the disease

is said to be idiopathic. For example, thecause of most hypertension (~90%) is

idiopathic. This type of hypertension iscalled primary hypertension.


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Different Categories ofDiseases:

Infectious versus Chronic Infectious Diseases (also called Communicable

Diseases) are caused by microscopic pathogenssuch as bacteria and viruses. These diseases canbe transmitted from one person to another.

Chronic diseases are NOT caused by pathogens.They are, for the most part, caused by behaviorssuch as smoking, sedentary lifestyles, inappropriateeating, and obesity. Chronic diseases are nottransmittable, i.e., they are not communicable.

Most of the diseases confronting the industrializednations (U.S., England, France, Germany, Australia,etc.) are Chronic diseases.

Worldwide, infectious diseases still kill more peoplethan do the chronic diseases.


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Where have the Infectious

Diseases Gone? The Infectious Diseases continue to kill more

people than the Chronic Diseases on a Worldwidebasis.

But, in the Industrialized Nations (e.g., U.S. &Europe) the Chronic Diseases are the major killers.

In the U.S. we have been successful in control ofthe Infectious Diseases through Public HealthEfforts (increased sanitation measures and personalhygiene, control of refuge, potable drinking waterand inoculation)

In the Developing Nations (e.g., Africa &Bangladesh) Public Health efforts lag behindresulting in more deaths from the infectiousdiseases.


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Predisposing Factors

Factors which predispose a person (increase thechances) for disease are called risk factors. Riskfactors do not cause the disease, per se, but theyincrease the odds of the disease occurring. Riskfactors are divided into 5-categories:

1. Age2. Sex3. Environment

4. Lifestyle5. Heredity Risk factors are subdivided into controllable and

non-controllable factors.


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Uncontrollable Risk Factors:

Age, Sex, HeredityAge: The older we become, the higher our

risk for disease especially the ChronicDiseases (a.k.a., Lifestyle Diseases)

Sex: Some diseases are more prevalent(common) in one gender or the other. Mencan contract prostate cancer, womencannot. Women are more likely to get

breast cancer than men.Heredity: Some disease run in families.Some of these are clearly a genetic disorderothers are referred to as heredofamilial.


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Partly Controllable to Non-

Controllable: EnvironmentThe environment includes such things

as the quality of the water we drink,

the quality of the air we breathe, andsanitation. Included in this list areenvironmental stressors such as noise

levels and over-crowding conditions.


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Lifestyle - Controllable

Lifestyle plays a role in all diseases butespecially chronic diseases. Ones

lifestyle is the sum total of their usualbehaviors. How one lives impliesbehavioral choices. Whether or notone smokes, exercises, eats a healthy

diet and maintains a healthy bodyweight are examples of behavioralchoices. Lifestyle risk factors arecontrollable.


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The Role of Risk Factors

for Chronic Diseases

LIFESTYLE: 53%

exercise, smoking,dietENVIRONMENT: 21%

HEREDITY: 16%

MEDICAL CARE:10%


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Infectious versus Chronic

INFECTIOUSDISEASES

CHRONICDISEASES

Cause: (Single causative)Microorganisms Cause: (Multicausative)Lifestyle, environment, genetics

Onset: Abrupt, Sudden Onset: Gradual, Insidious

Duration: Finite, Predictable Duration: Indefinite, Often fora Lifetime

Recovery following Treatment:Rapid

Recovery following treatment:Ill-defined


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The Role of Medicineversus Education

Death High-Level Health

No Discernible Illness

Symptoms

Signs

Education to reduceRisk Factors

No Smoking, Healthy Diet,Exercise, Weight Control

Medicine Drugs &Surgery

The Medical System is a Passive System It is activated by a sickperson. Education (pro-active) seeks to prevent Illness in the firstplace.


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Signs & Symptoms

Signs of disease states are objective. Theycan be measured. For example, bloodpressure is measured with a

sphygmomanometer (blood pressure cuff).Blood pressure is quantified as millimetersof mercury (mm/Hg).

Symptoms are feeling a person has asreported to the physician. For example,headaches.

Sometimes a symptom can also be a sign.For example, a runny nose.


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Diagnosis & Prognosis

The identifying and naming of a disease isthe diagnosis of a disease. Before anydisease can be treated, the disease must beidentified.

Prognosis is the predicted or expectedoutcome of the disease. For example, theprognosis of the common cold is completerecovery within 7 to 10 days. The prognosisof lung cancer is not good. Most who arediagnosed with lung cancer will not survive5-years.


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Diagnosis Three Parts

Diagnosis is made by:

1. A complete Medical History of the

sick person

2. A Physical Examination of the sickperson

3. Data collected in Laboratory Tests.


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Remission & Exacerbation

If a disease goes into remission, thesymptoms are significantly diminished ortemporary resolved.

Exacerbation refers to a time whensymptoms flare up or become worse.

Complications are said to occur when a

second disease occurs in an alreadydiseased person. For example, a personwith a broken arm may suffer from boneinfection.


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Iatrogenesis

& NosocomialIatrogenic problems stem from the medical

treatment. For example, chemotherapy can

cause anemia; mammography may increasethe risk of breast cancer.

Nosocomial means the disease was acquiredin a hospital environment. Septicemia

(infection) is a leading cause of death in theU.S.


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Morbidity & Mortality

Mortality refers to death. Mortalityrates express the number of fatalities

for a particular disease.Morbidity refers to sickness (illness)

rates.


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Treatment

Once a disease has been diagnosed (given aname) treatment interventions can bedecided upon.

Treatment may include medications (drugs),surgery, physical therapy, exercise, dietarymodifications, and education.

The concept of treatment should be holistic,

i.e., treatment of the person and not justthe disease.Palliative treatment seeks to prevent pain

and discomfort but does not seek a cure.


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Ethical Issues

Ethics concerns itself with moral issues therightness or wrongness of decisions.A major issue confronting us today is the

rightness or wrongness ofEuthanasia. Do youthinkMercy Killingis good or bad and why? Do you want Heroic Measuresimplemented to save

your life? How about the life of a loved one?Why do we consider putting our pets asleep a

humane measure but dont think its humane to puta human out of misery?Who should make Life-or-Deathdecisions? You?

Doctors? Courts?


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Questions to Ponder

Why do you think it is important to study human diseases? What are the major diseases (categories) challenging people

living in West Virginia and the United States? How important is it for us to control risk factors?

Why do we refer to the medical-care system as a passivesystem? Why is Education called Pro-Active? What are the major risk factors for lifestyle diseases? Differentiate between Infectious Diseases and Chronic

Diseases in terms of: Cause, Onset, Duration, and Recoveryafter Treatment.

What is the percent contribution of Lifestyle to the ChronicDiseases? What are the three parts of a medical diagnosis and which is

most important to the physician? Do you think its important that we set-an-example for our

children and loved ones in the fight against chronic illness? Is

it important that teachers who teach health be role models?


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TermsDo you Understand them?

What do the following terms mean?1. Disease2. Disorder3. Symptoms4. Signs

5. Syndrome6. Homeostasis7. Pathology8. Etiology9. Chronic10. Infectious11. Idiopathic12. Diagnosis13. Prognosis14. Morbidity15. Mortality

16 Passive versus pro-active

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Intro to Diseases1