Essentials of Human Diseases and Conditions

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Essentials of Human Diseases and Conditions

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Chapter 1Mechanisms of Disease, Diagnosis, and
Treatment
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Learning Objectives

• Explain how a pathologic condition affects the
  homeostasis of the body.
• Describe the difference between signs and
  symptoms of disease, acute and chronic disease,
  benign and malignant disease.
• Identify the predisposing factors of disease.
• Describe the ways in which pathogens may cause
  disease.

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Learning Objectives (contd.)

• Track the essential steps in diagnosis of
  disease.
• List the prevention guidelines for cancer.
• Explain the inflammation response to disease.
• Describe the hospice concept of care.
• Name two ways an individual can practice positive
  health behavior.

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Learning Objectives (contd.)

• Describe the physiology of pain, how pain may be
  treated, and what is meant by referred pain.
• Define the holistic approach to medical care.
• Describe examples of alternative medical
  therapies.
• Discuss the principles and goals of patient
  teaching.

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Pathology at First Glance

• Homeostasis internal stability of the body
• Pathology abnormal condition causing measurable
  changes in structure and function
• Pathogenesis development of disease in stages

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Pathology at First Glance (contd.)

• Systemic health Internal equilibrium
• Disease state Inability to adapt to
  internal/external stressors or challenges
• Syndrome Defined collection of signs and
  symptoms that characterize a condition

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Pathology at First Glance (contd.)

• Signs
• Abnormal objective findings
• Examples redness, swelling, purulent discharge,
  fever
• Symptoms
• Subjective patient reports
• Examples difficulty swallowing, pain, fatigue,
  headache

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Pathology at First Glance (contd.)

• Acute Illness
• onset is usually abrupt
• symptoms present themselves over hours to days
• duration brief (
• Chronic Illness
• onset is slower
• symptoms persist from acute/subacute phases
• duration indefinite ( 6 months)

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Mechanisms of Disease

• Genetic Diseases
• Genetic mutations changes in the genetic code
  that
• are passed from one generation to the next
• may occur spontaneously
• may be caused by agents that disrupt the normal
  DNA sequence

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Mechanisms of Disease (contd.)

• Modes of Inheritance for Genetic Diseases
• Autosomal dominant single abnormal gene on only
  one of a chromosome pair will cause disease
• Autosomal recessive same abnormal gene present
  on both chromosomes of a pair
• X-linked (sex-linked) recessive abnormal gene is
  only located on an X chromosome

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Mechanisms of Disease (contd.)

• Infection
• Modes of transmission include
• Direct or indirect physical contact
• Body fluids/blood
• Inhalation
• Ingestion
• Insect/animal

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Mechanisms of Disease (contd.)

• Infection
• Pathogenic agents include
• Bacteria
• Viruses
• Fungi
• Protozoa

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Mechanisms of Disease (contd.)

• Infection
• Bodys defense systems against infection
• natural mechanical and chemical barriers
• inflammatory response
• immune response

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Mechanisms of Disease (contd.)

• Inflammation and Repair
• Acute inflammatory response is marked by
• Redness
• Heat
• Swelling
• Pain
• Loss of function

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Mechanisms of Disease (contd.)

• Inflammation and Repair
• Acute inflammatory response can be inhibited by
• Immune disorders
• Chronic illness
• Medications, especially steroids

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Mechanisms of Disease (contd.)

• Cancer
• A group of diseases characterized by uncontrolled
  cell proliferation or growth.
• The uncontrolled growth proliferates at the
  expense of healthy cells and tissues.
• The uncontrolled growth can develop into masses
  of abnormal cells or tumors.

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Mechanisms of Disease (contd.)

• Cancer
• Benign tumors
• develop slowly
• can arise from any tissue
• usually remain encapsulated (self-contained)
• rarely recur after surgical removal

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Mechanisms of Disease (contd.)

• Cancer
• Malignant tumors
• cells multiply rapidly
• do not usually resemble the tissue of origin
• invade surrounding tissue
• often recurrent
• infiltrate to distant sites (metastasize)

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Mechanisms of Disease (contd.)

• Cancer risk factors
• tobacco smoke (active and passive)
• heavy use of alcohol
• exposure to environmental carcinogens
• high fat/low fiber diet
• excessive exposure to sunlight/UV light
• sedentary lifestyle
• exposure to radiation/radon

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Mechanisms of Disease (contd.)

• Cancer screening guidelines
• Men
• PSA test (prostate-specific antigen)
• Testicular self-exam
• Women
• Pap smear
• Mammogram
• Breast self-exam

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Mechanisms of Disease (contd.)

• Cancer Treatment
• surgery
• radiation
• chemotherapy
• hormone therapy
• immunotherapy
• Palliative surgery

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Mechanisms of Disease (contd.)

• Hospice Care
• comfort and supportive care for the patient and
  family during the terminal stages of illness and
  into the bereavement period
• emphasis on palliative treatment
• neither hastens nor postpones death
• considers dying as a normal process
• provides physical, psychological, and spiritual
  support
• may be home-based or in a facility with dedicated
  hospice services/beds

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Mechanisms of Disease (contd.)

• Predisposing Factors
• age
• gender
• lifestyle
• environment
• heredity

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Mechanisms of Disease (contd.)

• Non-changeable predisposing factors
• age
• gender
• heredity

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Mechanisms of Disease (contd.)

• Changeable predisposing factors
• Lifestyle
• physical abuse and violence
• poor nutrition
• tobacco, drugs, and alcohol
• Environment
• air and water pollution
• chronic stress

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Mechanisms of Disease (contd.)

• Preventive health care
• positive personal health behaviors
• modification of identified risk factors
• prophylactic medical services
• environmental and workplace safety

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Mechanisms of Disease (contd.)

• Immune disorders
• hypersensitivity reaction (allergy)
• autoimmune disease
• immunodeficiency disorder

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Mechanisms of Disease (contd.)

• Hypersensitivity reaction
• Exposure to allergen, which acts as antigen
• Triggers release of histamine, etc.
• Symptoms produced (mild to life-threatening)

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Mechanisms of Allergic Reaction
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Mechanisms of Disease (contd.)

• Aging Process
• metabolic changes (e.g., decreased liver kidney
  function)
• decreased total body water
• changes in body composition (e.g., increased
  adipose tissue, decreased muscle mass)
• decreased bone density

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Mechanisms of Disease

• Pain Physiology
• stimulation of nociceptors found on free nerve
  endings
• impulses travel through spinal cord to brain
• usually signals injury or tissue damage
• may travel a parallel pathway along spinal cord
  to brain, resulting in referred pain in another
  part of the body

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Mechanisms of Disease (contd.)

• Pain Medications
• analgesics
• opioids (narcotics)
• non-steroidal anti-inflammatory drugs (NSAIDS)
• antidepressants
• anticonvulsants
• antispasmodics

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Mechanisms of Disease (contd.)

• Psychological Pain
• feelings of sadness, despair, anger, depression,
  helplessness, hopelessness
• thought processes may be impaired
• sleep patterns may be disrupted
• may exhibit changes in personality
• may cry or show signs of withdrawal

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Mechanisms of Disease (contd.)

• Diagnosis of Disease
• medical history
• physical exam
• laboratory tests (blood count, chemistry, etc.)
• imaging tests (MRI, CT, X-ray, ultrasound, etc.)
• biopsy
• miscellaneous tests (pulmonary function,
  cultures, etc.)

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Mechanisms of Disease (contd.)

• Holistic Medical Care
• Focuses on the needs of the whole person
• physical
• spiritual
• psychological
• social
• emotional
• intellectual

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Mechanisms of Disease (contd.)

• Cultural Diversity
• Individuality based on numerous differences
• race
• ethnicity
• language
• culture
• religious beliefs
• values/life experiences

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Mechanisms of Disease (contd.)

• Alternative Medicine
• Therapies complementary to traditional medicine
• osteopathy
• acupuncture and acupressure
• massage and reflexology
• relaxation therapy
• herbal/nutritional supplements
• chiropractic
• hypnosis

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Mechanisms of Disease (contd.)

• Genetic Counseling
• Communication process that revolves around the
  occurrence of or potential for a genetic disorder
  within a family
• Genetic testing may be recommended
• Test results, risks of disease development, and
  available treatment options discussed

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Mechanisms of Disease (contd.)

• Gene therapy
• Experimental intervention repairs or blocks the
  expression of specific genes to treat disease.
• The disease treated with gene therapy may be
  either inherited or acquired.

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Patient Teaching

• Goals of patient teaching
• facilitate patient compliance with the medical
  treatment plan
• clarify information and instructions
• foster patient independence and responsibility
• establish trusting, therapeutic relationship

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Patient Teaching (contd.)

• Additional reasons for patient teaching
• ease anxiety
• facilitate greater sense of patient control
• improve patient/family coping
• highlight goals for recovery or acceptance
• reduce unnecessary clinic visits and
  hospitalizations