11-10-21 - Classification of Disease Flashcards
What is disease?
• Disease is a disorder of function in a human that produces specific symptoms and/or affects a specific location and is not simply the result of direct injury.
How do we classify conditions?
What are examples of this?
- Functional – this could be a sore head – this is not enough detail, and could be for any number of reasons.
- Biological – haemorrhage, tumour, trauma – this gives more detail than functional classification
- Socioeconomic and health – Related to something that has happened due to socioeconomic patterns of behaviour – a hangover
- Functional again – vascular anomaly, migraine
- Systems or precision medicine – any or all of the above
What is aetiology?
What is pathogenesis?
What is sequalae?
What does morphological mean?
- Aetiology is the cause, set of causes, or manner of causation of a disease or condition (cause)
- Pathogenesis – the manner of development of a disease.
- Morphological – relating to the form or structure of things.
- Sequelae – a condition which is the cause of a previous disease or injury
What are the 6 characteristics of disease?
- Aetiology
- Pathogenesis
- Manifestations (clinical, morphological, functional)
- Complications
- Outcome
- Epidemiology – particular outcome for certain people?
What are the 5 factors of identification of cause
- Probability of disease – someone who smokes a lot has a higher probability of lung cancer, yet 4% of those with lung cancer don’t smoke
- Host predisposition – prostate cancer more likely in African Americans as they have a genetic predisposition for it.
- Cause
- Causal associations – chain of events (this causes this causes this)
- Kochs postulates
What are Koch’s postulates used for?
What are Koch’s postulates?
- Kochs postulates are used when evidence is required to stablish an etiologic (aetiology) relationship between microorganisms and disease
- Koch’s postulates:
- Microorganisms must be observed in every case of the disease
- It must be isolated and grown in pure culture
- The pure culture, when inoculated in animals, must reproduce this disease
- Microorganism must be recovered from the diseased animal
What 4 different categories can cause be a part of?
What is an example?
- Genetic
- Environmental – infection, chemicals, radiation, medical trauma
- Combination (multifactorial)
- Unknown – primary, essential, idiopathic, spontaneous, cryptogenic (all unknown)
- E.g diabetes – there is a strong genetic predisposition for diabetes, but obesity puts the person at increased risk.
What is pathogenesis?
What are examples of pathogenesis?
How are aetiology and pathogenesis linked?
- The manner of development of disease
- Examples – inflammation, degeneration, carcinogenesis, immune reactions (allergy)
- The same aetiology may lead to different pathological endpoints e.g haemophilus influenza can cause sniffles, meningitis, pneumonia
- The same end point may reflect different aetiology e.g cirrhosis of the liver can be caused by alcoholism or obesity
What are the 6 structural manifestations of disease?
What is an example of this?
- Space-occupying lesion
- Deposition of abnormal material
- Abnormally sited tissue
- Loss of healthy tissue
- Obstruction of a tube
- Rupture of hollow viscus
- E.g tumour growing in the head – manifestations related to the fact there is a tumour growing inside limited amount of space
What are the 4 functional manifestations of disease?
What is an example of this?
- Excessive secretion of cell product
- Insufficient secretion of cell product
- Impaired nerve conduction
- Impaired muscle contraction?
- E.g tumour may produce a hormone – patient prevents with effects of producing too much anti-diuretic hormone
Nomenclature of disease
- Primary vs secondary – myocardial ischaemia secondary to diabetes, need to deal with both
- Acute vs chronic – acute is a sudden onset, chronic is developing slowly over time
- Benign vs malignant – benign tumours stay in their primary location without invading other sites in the body. Malignant tumours may infiltrate and spread somewhere else
- Eponymous name – diseases named after a person e.g Parkinson’s or Alzheimer’s
- Syndrome vs disease – a syndrome is a collection of things that could be regarded as disease on their own, hence the name syn-drome
- Disorders of growth – anything from too few to too many cells and gong out of control
- Inflammation and repair – acute? Chronic? Fibrous repair? Scarring? Regeneration
- Degeneration – decline/deterioration
- Thrombosis, blood coagulability – thrombosis is blood clots forming in the blood vessels
Why do we classify disease?
What is prognosis, treatment, prediction and epidemiology?
- We classify disease in order to understand, communicate, and pass on accurate information e.g patient to clinician, clinician to clinician, clinician to laboratory
- Prognosis – what is going to happen to the patient
- Treatment – what we can treat the patient with
- Prediction – if we give the treatment, will it work?
What is the TNM staging system used for?
- The TNM staging system is used to describe the extent and severity of someone’s cancer
- T – extent of tumours
- N – whether cancer cells have spread to local lymph nodes
- M – Whether cancer cells have spread to other parts of the body (has metastasis occurred)
What is epidemiology?
What 4 areas does it assess?
What 5 things is it affected by?
- Epidemiology is the study and analysis of distribution, patterns, and determinants of health and disease conditions in defined populations
- Incidence - number of cases happening per period of time
• Prevalence – Number of people in a population who have a particular disease at a specified appoint in time
• Remission – a decrease in severity or disappearance of disease
• Mortality - death rate - Epidemiology is affected by:
- Age
- Time
- Geography
- Socioeconomic factors e.g income, education, employment
- Occupational factors – health outcome among workers e.g noise, chemicals, heat, radiation in their environment
Why might mortality from ischaemic heart disease by different in developed countries?
- Some countries are generally healthier than others
- There may be a difference in how deaths are reported in each country, which is why it is important that everything is standardized.
What are the 4Ps of medicine? What is personalised medicine? Why is it important?
- 4P Medicine – personalised, predictive, participatory, preventive
- Personalised medicine aims to include patients in their treatment
- This is because we are treating a patient with a disease, not just a disease
- This will allow for a better experience for the patient, and hopefully allow us to treat them better.