Pathology is the study of disease and disease processes. It aims to determine the cause, understand the mechanisms, and describe the effects and progression of diseases. Pathology explains how diseases cause observed symptoms by detailing the steps from risk factors to physiological disruption to resulting body changes and responses. Understanding the pathology, epidemiology, etiology, pathogenesis, clinical manifestations, investigations, natural history, and management of a disease is important for pharmacy students to properly diagnose, treat, and communicate with patients and other healthcare professionals.

1. Pathology & Disease Terminology
Kamran

2. Pathology
• Study of disease or suffering
• Describes the effects, progress and consequence of
the disease
• Attempts to determine the cause (etiology) and
underlying mechanisms (pathogenesis)
• Since the disease effect the structural and
functional components of cell, tissue or organ of
the body, it is the "scientific study of the molecular,
cellular, tissue, or organ system response to
injurious agents."

3. • Pathology answers the question:
• How the disease cause the observed system?
• Ideally, it explains the steps by which the
etiological risk factors lead to malfunctioning
• It then describes the changes caused in the
body function resulting from the disease and
the body’s response to this

4. Pathophysiology
• Relates the effects of disease to the disruption
of normal physiological functions, e.g.,
• The pathophysiology of essential hypertension
involves a raised peripheral vascular resistance
and possibly an expansion of intravascular
fluid volume
• Immunopathology-Study of immunological
processes involved in the development of
autoimmune disease

5. Goals of Pathology for a Pharmacy Student
• Be able to understand and analyze the relationship
between pathologic changes and clinical
manifestations
• Be able to take a clinical history somewhat similar
to physicians / surgeons
• Be able to develop a superficial diagnosis
• Be able to communicate with professionals and
patients
• Be able to distinguish the drug related problems
from the disease sequels

6. HEALTH & DISEASE
• Health- a state in which an individual is living
in complete harmony with his environment
• a relative state
• WHO definition of Health- A state of
complete physical, mental and social well-
being and not merely the absence of disease
or infirmity

7. • Disease- a state in which an individual exhibits
an anatomical, physiological, or biochemical
deviation from the normal – dysfunction of
normal homeostasis
• An account of a disease starts with a
description of its general nature, including the
organ system affected and important features
that differentiate it from similar conditions

8. • Essential Hypertension is a chronic slowly
progressive cardiovascular condition in which the
mean BP is consistently above the population
normal range for the patient’s age, but below 130
mmHg and not rapidly rising
• RA is a severe chronic progressive inflammatory
erosive polyarthropathy, primarily articular synovitis
but with systemic features

9. • A disease can fall in one of the following
categories:
• Developmental
• Inflammatory
• Neoplastic
• Degenerative

10. What should we Know About A Disease
• Definition
• Epidemiology-where &when?
• Etiology-what is the cause?
• Pathogenisis-evolution of dis.
• Morphology-structural changes
• Functional consequences
• Management
• Prognosis
• Prevention
PATHOLOGY

11. Epidemiology
• Incidence- the no. of new cases of the disease;
usually expressed as per million of a poulation/year
• Lifetime incidence- the proportion of the
population likely to suffer from the disease at some
time in their life
• Prevalence- no. of active cases of the disease at any
one time, e.g., the overall prevalence of Parkinson’s
disease is about 1 in 1000, affecting men and
women equally but is 1 in 200 among those over 70
years of age

12. • Morbidity- sometimes used more loosely to
describe the prevalence of a disease; thus, heart
disease has a relatively high morbidity; renal cancer,
a low morbidity
• Comorbidity- refers to any other disease, the
patient has
• Mortality- no. of deaths that result from disease
• Predisposing Causes of Diseases - those factors
which make an individual more susceptible to a
disease (damp weather, poor ventilation, etc.)

13. Etiology
“Study of the cause of a disease"
• An etiologic agent :
is the factor (bacterium, virus, etc.) responsible for lesions or a disease state.
• Predisposing Causes of Disease:
Factors which make an individual more susceptible to a disease (damp
weather, poor ventilation, etc.)
• Exciting Causes of Disease:
Factors which are directly responsible for a disease (hypoxia, chemical
agents…. etc.).

14. • One etiologic
agent several
diseases, as
smoking.
Disease
• Several etiologic agents
one disease, as diabetes .
Disease
Disease
DiseaseDisease
One etiologic agent
- one disease, as
Malaria.
Etiology

15.  Environmental agents:
• Physical
• Chemical
• Nutritional
• Infections
• Immunological
• Psychological
 Genetic Factors:
• Age
• Genes
Multifactorial:
As Diabetes,
Hypertension
Cancer
Etiology:
What is the cause?

16. pathogenesis
The sequence events in the response of the cells or tissues to the
etiologic agent, from the initial stimulus to the ultimate
expression of the disease,”from the time it is initiated to its final
conclusion in recovery or death”
The core of the science of pathology — the
study the
pathogenesis of the disease.

17. Morphology: Structural Changes
Structural changes in disease.
Tumor in a cancer.
Ulcer in an infection.
Atrophy in dementia.
Gross & Microscopic.

18. Clinical Symptoms & Signs
• Clinical signs are seen only in the living individual.
• “Functional evidence of disease which can be determined
objectively or by the observer" (fever, tenderness, increased
respiratory rate, etc.)”
Clinical symptoms are the patient’s
complain usually by its own words.

19. Clinical Features
• Symptoms- subjective noticed by patient and either
reported or elicited on questioning
• Signs- objective and noticed by the clinician on
examination, although occasionally may be noticed by
the patient
• Clinical Presentation- the typical pattern of clinical
features caused by a disease
• Pathognomonic- Many disease have such consistent
presentation to be almost diagnostic, e.g., a spiking
fever, stiff neck and photophobia in meningitis; such
definitive features are called pathognomonic
• Syndrome- A well defined group of clinical features that
commonly occur together ,e.g., proteinuria,
hypoproteinemia and edema together ‘nephrotic synd.’

20. Investigations
• Provincial diagnosis
• Differential diagnosis
• Confirmed diagnosis

21. Natural History of the Disease
• Knowledge of the disease from its onset to final
outcome is important for its management
• Prognosis- the probably outcome of a disease in a
living individual (cure, morbidity or mortality)
• If RA has a sudden onset of multi-joint
inflammation, the prognosis is better
• Knowing the average duration of the disease and its
pattern is also important

22. • Prodromal Phase- a period of characteristic warning
signs, some diseases starts with.
• Acute illness-Starts suddenly (acute onset) and
resolves either of its own accord or following
treatment
• Chronic disease- starts insidiously and continues for
a long time, possibly lifelong
• Progressive disease- if a chronic disease tend to
deteriorate steadily, it is called progressive disease

23. Disease Management
• A strategy to deal with the patients’ complaint,
starting with developing realistic aims based on a
knowledge of the presentation, investigations and
natural history and then targeting the complaints
with different interventions such as drugs, surgery
• Palliative care- In very advanced or incurable
disease, the management might involve no more
than symptom control, nursing care, simple
reassurance and appropriate counseling; this is
called palliative care

24. Aims
• Several aims for different aspects of the disease
• Prophylaxis as in COPD & ischemic heart disease
• Reversal as in minor diseases which are intrinsically
temporary, self-limiting and reversible, i.e., minor
gastric upsets—Transplantation is another area
• Arrest progress as in RA where the aim is to slow,
arrest or stabilize the condition, preventing
deterioration and minimizing exacerbations or
relapse
• Symptomatic relief and palliation as in minor self
limiting conditions; OTC medications used

25. Case History
• Is a systemic account of the progress of a patient’s
disease including the information and reasoning
behind diagnosis and management decisions
• Taking a ‘good history’ is a subtle mixture of
comprehensive clinical knowledge, detective work,
lateral thinking and communication skills such as
listening and questioning

26. • A case history is composed of
• Patient details
• Past medical history (PMH)
• Medication history
• Family history (FH)
• Social history (SH)
• History of presenting complaints (HPC)
• Systemic examinations (review of symptoms)
• Investigations (Ix)
• Diagnosis (Dx)
• Management (Rx) including aims, modes,
monitoring and outcome(s)

27. • Patients details: Age, sex, occupation, build, weight,
race, ethnic group, place of residence, recent travel
• Past Medical History (PMH): Illness since childhood
(including current chronic conditions)
• Medication History: Current medication
(prescription, OTC)- effectiveness and ADRs, past
medication problems
• Family History (FH): Relative (living or dead)
• Social History (SH): Social drug use, domestic &
financial situation, mobility; how is patient coping
(home, work and leisure)

28. • History of Present Complaints (HPC, complaints of):
Onset, nature and intensity of symptoms, changes,
provoking and relieving factors, referrals & outcomes,
medications (about 75% of diagnosis)
• Systemic examination (review of systems): Should be
objective and complete; starts with general appearance
& condition of the patient, especially coloration, body
surface markings etc; presence or absence of jaundice,
anemia, cyanosis & edema; This includes:
– Direct questioning about symptoms
– Observation & examination for physical signs
– Palpation (feeling)
– Auscultation (listening with a stethoscope)
– Percussion (tapping an area and listening to the sound)

29. • Investigations (Ix): involve BP & blood sugar
measurement, blood biochemistries, ECG, X-ray etc
• Diagnosis (Dx): provisional, differential or confirmed
• Management (Rx): Mgt. plan includes realistic aims
for each complaint and moods prescribed to meet
them, monitoring & expected outcomes; complaints
– The current complaint-an active complaint; hypertension
– Important PMH (either active-peptic ulcer or inactive- a
past MI)
– Behavior that requires modification- smoking, poor diet
– Possibly psychological & social problems
• Every complaint is addressed with a plan

30. Drug Therapy
• Drug therapy is one of the modes of treatment for
patient complaints
• Drug therapy decision involves the thought process
for drug selection depending upon:
– clinical factors (diagnosis & clinical features such as
etiology, pathology & severity),
– patient factors (age, genetic, racial, non-compliance,
poor communication, concurrent diseases, tolerance,
idiosyncrasy) and
– drug factors (PK/PD, toxicity, pKa, molecular size,
solubility, biopharmaceutical factors)

31. Clincal factors:
Diagnosis, specific
clinical features
(etiology, pathology,
severity)
Several possible drug groups
Preferred drug group
Preferred group member
Route, Dose, Formulation
Drug Therapy Indicated
Patient
Factors
Drug Factors

32. Evidence Based Medicine
• Patient Mgt.: priorly based on observational studies
and expert opinion; now moving to evidence based
medicines on critical & objective comparison of the
clinical outcomes of different treatments
• Based on meta-analysis
• If not available, less rigorous systemic reviews of
RCTs (randomized controlled trials)
• If RCT not available, case control or cohort can be
used
• Least reliable are individual case reports or expert
opinion