To facilitate working with SNOMED CT, each top-level concept has its own dedicated icon which is also used for its children (e.g. a heart icon for clinical findings). This way, you can easily distinguish the different top-level hierarchies from each other, no matter where you are working within the hierarchy or what function of Snow Owl you are using.
You can find below the icons that are used in Snow Owl to identify top-level concepts accompanied by a bit of information about their content:
Icon
Description
Also called as root concept
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Normal (e.g. Entire femur) or abnormal (e.g. Vascular polyp) body structures. Anatomically abnormal body structures are found in the Morphologically altered structure sub-hierarchy.
Outcomes of clinical observation, assessment, or judgment, as well as normal and abnormal (e.g. Pulse fast) states. Clinical states that are necessarily abnormal (e.g. Acute allergic reaction) are found in the Disease sub-hierarchy.
Different types of environments (e.g. Intensive care unit, Toxic environment, Cold zone) and locations such as countries, states, and regions (e.g. Burundi, Arizona, Island in the region of North America).
Occurrences (e.g. Accident, Exposure to carbon dioxide, Air travel, Environmental event).
Procedures and interventions are excluded from this category.
Entities that can be measured or observed (e.g. Age at first symptom, Blood pressure, Body temperature).
Organisms that are relevant in human and veterinary medicine such as animals (e.g. Canis lupus familiaris), plants (e.g. Amaryllis), life-cycle forms (e.g. Bacterial spore), trophic life forms (e.g. Carnivore), chromista (e.g. Oomycota), and microorganisms (e.g. Fungus).
Drug products (e.g. Oral form aspirin, Alcoholic disinfectant, Lavender oil).
This hierarchy has to be distinguished from the substance hierarchy, in which the chemical constituents used in pharmaceutical products are represented.
Different kinds of physical influences that are connected to an injury. Examples: Detonation, Air and water pressure, Radiation, Mechanical stress
Devices (e.g. Industrial machine), materials (e.g. Leather), instruments (e.g. Firearm), vehicles (e.g. Snowmobile), and other natural or man-made objects (e.g. Hospital bed, Silver jewelry).
Activity in the healthcare sector such as administrative (e.g. Death certification, Formal complaint about GP), invasive (e.g. Removal of wart), diagnostic (e.g. Complete blood count), imaging (e.g. Radiography of shoulder), educational procedures (e.g. Diet education), as well as referrals (e.g. Referral by clinical oncologist)
Qualifier value concepts are used as values for other SNOMED CT attributes.
For example, the values for specifying the laterality of an ulnar fracture (i.e. Left, Right) are contained here.
Documents that were created to provide information about healthcare-related events or states of affairs (e.g. Anesthesia record, Birth certificate).
Concepts in this hierarchy specify the circumstances of a procedure, a finding, or a condition. They refer to procedures and conditions in the past (e.g. Injection given) or future (e.g. Awaiting radiotherapy), findings that can be ruled out (e.g. No cardiovascular symptom), or information about someone other than the patient (e.g. Family history of alcoholism).
Core metadata concepts (provides structural information for international releases), foundation metadata concepts (reference sets, reference set attributes), linkage concepts (attributes, link assertions), namespace concepts, module concepts (e.g. national extensions), etc.
Social aspects that may influence the health and treatment of a patient. Concepts refer to social status (e.g. Lower middle class economic status), ethnic group (e.g. Caucasian), religion (e.g. Anglican), lifestyle (e.g. Eating habit), family (e.g. Divorced parents), and occupation (e.g. Factory worker).
Inactive concepts (e.g. outdated concept) as well as some navigational concepts.
Samples or specimens that were acquired for examination or analysis. Examples: Blood sample, Genetic sample, Environmental swab, Specimen from bone marrow obtained by biopsy.
Concepts in this hierarchy refer to different instruments of testing and scaling: Assessment scales (e.g. Stanford Binet intelligence scale), classifications (e.g. Endometriosis classification of American Fertility Society), grading systems (e.g. Nottingham histologic grading system), symptom ratings (e.g. Chest pain rating), and tumor staging (e.g. Cancer staging).
Substances and chemical constituents that are used for pharmaceutical and biological products, as well as body, dietary, and diagnostic substances. Examples: Diclofenac, Melatonin, Urine protein, Swimming pool water.
SNOMED CT Concept
Body structure
Clinical finding
Environmental or geographic location
Event
Observable entity
Organism
Pharmaceutical / biological product
Physical force
Physical object
Procedure
Qualifier value
Record artifact
Situation with explicit context
SNOMED CT Model Component
Social context
Special concept
Specimen
Staging and Scales
Substance