| Attribute Type | Expanded Form | Count |
| LRN2 | Related names 2 | 112126 |
| PART_TYPE | Part type | 110984 |
| SEQ_NO | Sequence number | 108414 |
| VERSION_FIRST_RELEASED | Version first released | 101632 |
| LOINC_SYSTEM | LOINC system | 101632 |
| LCT | LOINC Change Type Code - type of change made to a LOINC term. | 101632 |
| COMMON_ORDER_RANK | Ranking of approximately 300 common orders performed by laboratories in USA | 101632 |
| LCS | LOINC status - valid values are "ACTIVE," "TRIAL," "DISCOURAGED," "DEPRECATED." For "DEPRECATED" or "DISCOURAGED" concepts, the term that should now be used may appear in the LMP element. | 101632 |
| LOINC_TIME_ASPECT | LOINC time aspect | 101632 |
| VERSION_LAST_CHANGED | Version last changed | 101632 |
| LOINC_COMPONENT | LOINC component | 101632 |
| LOINC_SCALE_TYP | LOINC scale type | 101632 |
| COMMON_SI_TEST_RANK | Corresponding SI terms for 2000 common tests performed by laboratories in USA | 101632 |
| LOINC_PROPERTY | LOINC property | 101632 |
| LCN | LOINC Classtype - 1 = Laboratory Class; 2 = Clinical Class; 3 = Claims Attachment; 4 = Surveys | 101632 |
| COMMON_TEST_RANK | Numeric ranking of approximately 2,000 common tests performed by hospitals | 101632 |
| LCL | LOINC Class - arbitrary classification of terms in LOINC designed to assist LOINC development and to group related observations together (e.g. ABXBACT = Antibiotic susceptibility) | 101632 |
| LOR | LOINC ORDER_OBS field. Defines term as order only, observation only, or both. Values are: BOTH OBSERVATION ORDER. A fourth category, Subset, is used for terms that are subsets of a panel but do not represent a package that is known to be orderable. | 86073 |
| LUR | Units required when used as OBX segment - a Y/N field that indicates that units are required when this LOINC is included as an OBX segment in a HIPAA attachment | 63666 |
| CONSUMER_NAME | An experimental (beta) consumer friendly name | 61708 |
| LOINC_METHOD_TYP | LOINC method type | 55382 |
| RADLEX_PREF_NAME | RadLex preferred name | 46784 |
| RID | Read Codes Term_id - identifier assigned to a Read term, used in referring to the term in the Read file structure, and may be used in clinical information systems. | 46784 |
| PART_SEQ_ORDER | Part sequence order | 46246 |
| EXAMPLE_UCUM_UNITS | The Unified Code for Units of Measure (UCUM) | 41725 |
| CATEGORY | Category | 41272 |
| EXAMPLE_UNITS | Example units | 38622 |
| CHANGE_REASON_PUBLIC | Detailed explanation about special changes to the term over time. | 31110 |
| ANSWER_LIST_ID | Answer list ID | 23482 |
| ANSWER_LIST_NAME | Answer list name | 23482 |
| ANSWER_LIST_OID | Answer list OID | 23482 |
| SOS | Scope Statement | 12731 |
| ANSWER_CODE | Answer code | 10216 |
| LQS | Survey Question Source | 9946 |
| LQT | Survey Question Text | 8183 |
| ASSOC_OBSERVATIONS | Associated observations | 8059 |
| HL7_ATTACHMENT_STRUCTURE | HL7 attachment structure | 7776 |
| EXTERNAL_COPYRIGHT_LINK | External copyright link | 7225 |
| COPYRIGHT | Copyright | 7225 |
| STATUS | Indicates status of "active" (current) or "inactive" (obsolete/deprecated) | 7076 |
| RADLEX_PLAYBOOK_LONG_NAME | RadLex Playbook long name | 6760 |
| RPID | RadLex Playbook ID | 6760 |
| IMAGING_DOCUMENT_VALUE_SET | A value of "TRUE" indicates that the LOINC NUM is a member of the Imaging Documents Value Set | 6678 |
| LEA | LOINC Example Answers - for some tests and measurements, LOINC has supplied examples of valid answers. These values differ from those in the ANSWERLIST field because that details possible values for nominal scale terms. | 4884 |
| PANEL_TYPE | Panel type | 4867 |
| LMP | LOINC Map to Code of the term that has superseded a term with a LCS value of DEPRECATED. | 4609 |
| STATUS_TEXT | Explanation of concept status in narrative text in LOINC | 3708 |
| STATUS_REASON | Classification of the reason for concept status in LOINC | 2724 |
| LOINC_SCORE | A numeric score associated with a LOINC answer ('LA') concept. | 1617 |
| UNIVERSAL_LAB_ORDERS_VALUE_SET | A value of "TRUE" indicates that the LOINC NUM is a member of the LOINC Universal Lab Orders Value Set | 1521 |
| MOLECULAR_WEIGHT_OF_ANALYTE | Molecular weight of analyte | 1454 |
| LFO | LOINC Formula - regression equation details for many OB.US calculated terms. | 701 |
| IEEE_REFID | IEEE REF ID | 646 |
| IEEE_CF_CODE10 | IEEE CF Code10 | 646 |
| EQUIVALENCE | Equivalence | 646 |
| ANSWER_CODE_SYSTEM | Answer code system | 119 |
| HL7_ATTACHMENT_REQUEST | HL7 attachment request | 109 |
| HL7_FIELD_SUBFIELD_ID | A value which indicates the content should be delivered in the named field/subfield of the HL7 message. When NULL, the data should be sent in an OBX segment with this LOINC code stored in OBX-3 and with the value in the OBX-5 | 97 |
| SUBSEQUENT_TEXT_PROMPT | Subsequent text prompt | 74 |
| ASK_AT_ORDER_ENTRY | Ask at Order Entry (AOE) observations for a clinical observation or laboratory test | 65 |
| DESCRIPTION | Description | 45 |
| USAGE_NOTES | Usage notes | 11 |
| Relation Name/Additional Label | Expanded Form | Count |
| RO/has_component | has relationship other than synonymous, narrower, or broader/Has component | 308584 |
| RO/component_of | has relationship other than synonymous, narrower, or broader/Component of | 308584 |
| CHD/ | has child relationship in a Metathesaurus source vocabulary /Empty relationship attribute | 278098 |
| PAR/ | has parent relationship in a Metathesaurus source vocabulary /Empty relationship attribute | 278098 |
| RO/class_of | has relationship other than synonymous, narrower, or broader/Class of | 267953 |
| RO/has_class | has relationship other than synonymous, narrower, or broader/Has class | 267953 |
| RO/system_of | has relationship other than synonymous, narrower, or broader/System of | 170126 |
| RO/has_system | has relationship other than synonymous, narrower, or broader/Has system | 170126 |
| SY/mth_expanded_form_of | source asserted synonymy./MTH expanded form of | 111856 |
| SY/mth_has_expanded_form | source asserted synonymy./MTH has expanded form | 111856 |
| RO/answer_to | has relationship other than synonymous, narrower, or broader/answer to | 108414 |
| RO/has_answer | has relationship other than synonymous, narrower, or broader/has answer | 108414 |
| RO/time_aspect_of | has relationship other than synonymous, narrower, or broader/Time aspect of | 101865 |
| RO/has_time_aspect | has relationship other than synonymous, narrower, or broader/Has time aspect | 101865 |
| RO/has_property | has relationship other than synonymous, narrower, or broader/Has property | 101632 |
| RO/scale_of | has relationship other than synonymous, narrower, or broader/Scale of | 101632 |
| RO/property_of | has relationship other than synonymous, narrower, or broader/Property of | 101632 |
| SY/has_common_name | source asserted synonymy./Has common name | 101632 |
| SY/common_name_of | source asserted synonymy./common name of | 101632 |
| RO/has_scale | has relationship other than synonymous, narrower, or broader/Has scale | 101632 |
| SY/expanded_form_of | source asserted synonymy./Expanded form of | 89048 |
| SY/has_expanded_form | source asserted synonymy./Has expanded form | 89048 |
| RO/measures | has relationship other than synonymous, narrower, or broader/Measures | 88303 |
| RO/measured_by | has relationship other than synonymous, narrower, or broader/Measured by | 88303 |
| RO/analyzes | has relationship other than synonymous, narrower, or broader/Analyzes | 80455 |
| RO/analyzed_by | has relationship other than synonymous, narrower, or broader/Analyzed by | 80455 |
| RO/has_method | has relationship other than synonymous, narrower, or broader/Has method | 76170 |
| RO/method_of | has relationship other than synonymous, narrower, or broader/Method of | 76170 |
| RB/has_member | has a broader relationship/Has member | 53314 |
| RN/member_of | has a narrower relationship/Member of | 53314 |
| RO/has_loinc_number | has relationship other than synonymous, narrower, or broader/Has Loinc number | 41272 |
| RO/loinc_number_of | has relationship other than synonymous, narrower, or broader/Loinc number of | 41272 |
| RO/has_suffix | has relationship other than synonymous, narrower, or broader/Has suffix | 24381 |
| RO/suffix_of | has relationship other than synonymous, narrower, or broader/Suffix of | 24381 |
| RO/supersystem_of | has relationship other than synonymous, narrower, or broader/Supersystem of | 22532 |
| RO/has_supersystem | has relationship other than synonymous, narrower, or broader/Has supersystem | 22532 |
| RO/challenge_of | has relationship other than synonymous, narrower, or broader/Challenge of | 18048 |
| RO/has_challenge | has relationship other than synonymous, narrower, or broader/Has challenge | 18048 |
| RO/has_evaluation | has relationship other than synonymous, narrower, or broader/Has evaluation | 12172 |
| RO/evaluation_of | has relationship other than synonymous, narrower, or broader/Evaluation of | 12172 |
| RO/has_imaged_location | has relationship other than synonymous, narrower, or broader/Has imaged location | 7064 |
| RO/is_imaged_location_for | has relationship other than synonymous, narrower, or broader/Is imaged location for | 7064 |
| RO/has_parent_group | has relationship other than synonymous, narrower, or broader/Has parent group | 7031 |
| RO/parent_group_of | has relationship other than synonymous, narrower, or broader/Parent group of | 7031 |
| RO/is_modality_type_for | has relationship other than synonymous, narrower, or broader/Is modality type for | 6660 |
| RO/has_modality_type | has relationship other than synonymous, narrower, or broader/has modality type | 6660 |
| RO/has_imaging_focus | has relationship other than synonymous, narrower, or broader/Has imaging focus | 6135 |
| RO/is_imaging_focus_of | has relationship other than synonymous, narrower, or broader/Is imaging focus of | 6135 |
| RO/divisor_of | has relationship other than synonymous, narrower, or broader/Divisor of | 5723 |
| RO/has_divisor | has relationship other than synonymous, narrower, or broader/Has divisor | 5723 |
| RQ/mapped_from | related and possibly synonymous./Mapped from | 4609 |
| RQ/mapped_to | related and possibly synonymous./Mapped to | 4609 |
| RO/is_lateral_anatomic_location_of | has relationship other than synonymous, narrower, or broader/Is lateral anatomic location of | 4004 |
| RO/has_lateral_anatomic_location | has relationship other than synonymous, narrower, or broader/Has lateral anatomic location | 4004 |
| RO/is_presence_of_lateral_location | has relationship other than synonymous, narrower, or broader/Is presence of lateral location | 3986 |
| RO/has_lateral_location_presence | has relationship other than synonymous, narrower, or broader/Has lateral location presence | 3986 |
| RO/is_aggregation_view_of | has relationship other than synonymous, narrower, or broader/Is aggregation view of | 3905 |
| RO/has_aggregation_view | has relationship other than synonymous, narrower, or broader/Has aggregation view | 3905 |
| RO/is_timing_for | has relationship other than synonymous, narrower, or broader/Is timing for | 2770 |
| RO/has_timing_of | has relationship other than synonymous, narrower, or broader/Has timing of | 2770 |
| RO/is_given_pharmaceutical_substance_for | has relationship other than synonymous, narrower, or broader/Is given pharmaceutical substance for | 2446 |
| RO/has_given_pharmaceutical_substance | has relationship other than synonymous, narrower, or broader/Has given pharmaceutical substance | 2446 |
| RO/associated_with | has relationship other than synonymous, narrower, or broader/Associated with | 2314 |
| RO/is_view_type_for | has relationship other than synonymous, narrower, or broader/Is view type for | 1991 |
| RO/has_view_type | has relationship other than synonymous, narrower, or broader/Has view type | 1991 |
| RO/is_pharmaceutical_route_for | has relationship other than synonymous, narrower, or broader/Is pharmaceutical route for | 1949 |
| RO/has_pharmaceutical_route | has relationship other than synonymous, narrower, or broader/Has_pharmaceutical_route | 1949 |
| RO/has_archetype | has relationship other than synonymous, narrower, or broader/Has archetype | 1365 |
| RO/archetype_of | has relationship other than synonymous, narrower, or broader/Archetype of | 1365 |
| RO/is_modality_subtype_for | has relationship other than synonymous, narrower, or broader/Is modality subtype for | 1181 |
| RO/has_modality_subtype | has relationship other than synonymous, narrower, or broader/Has modality subtype | 1181 |
| RO/has_action_guidance | has relationship other than synonymous, narrower, or broader/Has action guidance | 1156 |
| RO/is_action_guidance_for | has relationship other than synonymous, narrower, or broader/Is action guidance for | 1156 |
| RO/is_presence_guidance_for | has relationship other than synonymous, narrower, or broader/Is presence guidance for | 1028 |
| RO/has_presence_guidance | has relationship other than synonymous, narrower, or broader/Has presence guidance | 1028 |
| RO/has_object_guidance | has relationship other than synonymous, narrower, or broader/Has object guidance | 476 |
| RO/is_object_guidance_for | has relationship other than synonymous, narrower, or broader/Is object guidance for | 476 |
| RO/has_exam | has relationship other than synonymous, narrower, or broader/Has exam | 471 |
| RO/is_exam_for | has relationship other than synonymous, narrower, or broader/Is exam for | 471 |
| RO/has_maneuver_type | has relationship other than synonymous, narrower, or broader/has maneuver type | 444 |
| RO/is_maneuver_type_for | has relationship other than synonymous, narrower, or broader/Is maneuver type for | 444 |
| RO/is_approach_guidance_for | has relationship other than synonymous, narrower, or broader/Is approach guidance for | 349 |
| RO/has_approach_guidance | has relationship other than synonymous, narrower, or broader/Has approach guidance | 349 |
| RO/time_modifier_of | has relationship other than synonymous, narrower, or broader/Time modifier of | 233 |
| RO/has_time_modifier | has relationship other than synonymous, narrower, or broader/Has time modifier | 233 |
| RO/adjustment_of | has relationship other than synonymous, narrower, or broader/Adjustment of | 204 |
| RO/has_adjustment | has relationship other than synonymous, narrower, or broader/Has adjustment | 204 |
| RO/has_count | has relationship other than synonymous, narrower, or broader/Has count | 148 |
| RO/count_of | has relationship other than synonymous, narrower, or broader/count_of | 148 |
| RO/is_subject_of | has relationship other than synonymous, narrower, or broader/Is subject of | 34 |
| RO/has_subject | has relationship other than synonymous, narrower, or broader/Has subject | 34 |
