Chapter 1: General Concepts of Disease | Principles of Diagnosis Flashcards
What is disease?
any disturbance of the structure or function of the body
What does congenital mean?
something you are born with
It could not manigest until the body is under stress, or never at all.
E.g. You are at the Doctors office for a routine check-up and he finds something wrong with you. What is this finding called?
an incidental finding
concept: health is on a [blank].
continuum.
- health flutates from day-day, week-week, etc.
- -health fluctuates with age
What is a sign vs a symptom?
sign: physical findings of diease (see)
symptoms: subjective manifestations of disease (feel)
What is pathogenesis?
the manner in which disease develops
(the progression)
What is etiology?
the cause of the disease
Classifications of Disease
Vascular
- blood vessels
- e.g. peripheral artery disease, aortic disease, coronary artery disease
Classifications of Disease
Infectious (Inflammatory)
- chronic inflammation is bad and often related to lifestype
- longterm inflammation can lead to diseases
- e.g. asthma, rhematoid arthritis, ulcerative colitis and Crohn’s disease
Classifications of Disease
Neoplastic
- tumors
- e.g. myeloid leukemia, myeloproliferative neoplasm, & metastatic malignant neoplasm in the bone marrow
Classifications of Disease
Degenerative (Deficiency)
- genetic/congenital issues that lead to deficiency or lack of production of something
- e.g. Alzheimer’s, Parkinson’s, Huntington’s, ALS, spinal muscular atrophy
Classifications of Disease
Idiopathic (Iatrogenic)
- we don’t know why it is happening
- e.g. acute idiopathic polyneuritis, diffuse idiopathic skeletal hyperostosis
Classifications of Disease
Congenital
- something you are born with
- e.g. heart defets, neural tube defects, Down Syndrome
Classifications of Disease
Allergic (Autoimmune)
- immune system reacts to harmless substances, leading to the activation of immune cells
- can sometimes be hard to diagnose
- e.g. Type I Diabetes, Celiac Disease, Hashimoto thyroiditis, Crohn’s, MS, Lupus
Classifications of Disease
Endocrine (Environmental)
- sometimes casued by environmental factors or hormonal disruptors
- e.g. insulin resistance, thyroid disease, reproductive abnormalities, cancer
Classifications of Disease
Metabolic
- diseases of metabolism
- e.g. Type 1 Diabetes, Gaucher disease, Phenylketonuria (PKU)
List and describe the 3 stages of diagnosis.
- clinical history: look at family history, lifestyle etc.
- Physical examination: palpating and visualizing
- Differential diagnosis: list of possible conditions that share the same symptoms described, narrowed down
What is prognosis?
the eventual outcome of disease (outlook for recovery)
- e.g. good, poor, guarded
What is treatment?
- specific treatment: treats underlying cause
- symptomatic treatment: alleviates symptoms but does not influence course of disease
What is the Patient-Centered Approach of taking a clinical history?
List the 5 stages.
- history of current illness: chief complaint, severity, onset
- medical history: details of general health, prev. illnesses
- family history: disease that may run in the family
- social history: occupation, habits, alcohol/tobacco
- review of symptoms: symptoms other than disclosed in history of present illness
What goes into choosing a diagnostic test?
- cost
- invasive vs non-invasive
- appropriateness for question being asked
- false positive/false negative ratio
What is specificity?
the percentage of patients without disease misclassified as having disease
- true negatives (+ false positives)
What is sensitivity?
the percentage of patients with the disease misclassified as not having the disease
- true positives (+false negatives)
What is a clinical laboratory test?
- a test ot determine the concentration of substances that are frequently altered by disease in blood or urine
- determine concentration or activity of enzymes in blood
- evaluate organ function
- monitor response of certain cancers to treatment
- detect disease-producing organisms in urine, blood, feces
- determine response to antibiotics
Diagnostic tests: Imaging
What is an X-Ray?
- the use of high-energy radiation waves at lower doses to produce images for diagnosing disease
- can penetrate through tissues at varying degrees
- act on photographic film as the rays leave the body
Diagnostic tests: Imaging
What is radiopaque?
(during X-ray) appears white on film; high density tissues (like bone) abosrb most of the rays
Diagnostic tests: Imaging
What is radiolucent?
(during X-ray) appears dark on film; low density tissues allow rays to pass through
What is a CT scan?
computed tomography
* radiation detectors record the amoung of X-rays or ionizing radiation absorbed by the body and feed data onto the computer that reconstruct the image
* radiopaque and radiolucent tissues appear white and dark like in X-ray
* higher dose of radiation than X-ray
* screen for cancer
* detect abnormalities in organs that cannot otherwise be identified by X-ray
What is MRI?
magnetic resonance imaging
* computer-constructed images of body based on response of hydrogen protons in water molecules when placed in a strong magnetic field
* protons align in the direction of the magnetic field
* protons are temporarily dislodged and wobble when radiofrequency waves are directed at them
* protons emit a measurable signal that can be used to construct images
What is a PET test?
positron-emission tomography
* measures metabolism of biochemical compounds that are labeled with positron-emitting isotopes to measure organ function
* evaluate changes in blood flow in heart muscle following heart attack
* determine metablic activities of organ or tissue
* expensive, not widely available, requires a lot of resources
What is a radioisotope study?
radioisotope (radionuclide) studies
* evaluate organ funciton by determining rate of uptake and excretion of substances labeled with a radioisotope
* anemia, hyperthyroidism, pulmonary blood flow, cancer sprea, heart muscle damage
What is a cytology test?
the exam of a single cell type
* e.g. Papanicolaou smear: identifies abnormal cells in fluids or secretions for cervical or other cancers
What do these electrical activity tests measure: ECG, EEG, and EMG?
ECG: measures changes in electrical activity of heart (a.k.a. EKG)
EEG: measures electrical activity of brain and brain waves
EMG: measures electrical activity of skeletal muscle during contraction and at rest
What is an endoscopy?
an examination of the interior of the body using a rigid/flexible tubular instrument equipped with a lens and light source
What is an ultrasound?
mapping echoes produced by high-frequency sound waves transmitted into body; echoes reflect change in tissue density to produce images
