Conditions

Generate clinically realistic Condition resources with proper coding, categories, and relationships.

Categories

Every Condition MUST have a category from http://terminology.hl7.org/CodeSystem/condition-category:

• problem-list-item — chronic/ongoing conditions on the patient's problem list.
• encounter-diagnosis — conditions diagnosed during a specific encounter.
• health-concern — patient/provider-identified health concern (US Core).

A single condition can appear as both (e.g., diabetes is a problem-list-item AND an encounter-diagnosis when addressed during a visit).

Coding Systems

Use dual coding when possible (ICD-10-CM + SNOMED CT):

• ICD-10-CM: system = http://hl7.org/fhir/sid/icd-10-cm
• SNOMED CT: system = http://snomed.info/sct
• Include both in Condition.code.coding[] for interoperability.

Common Conditions by Specialty

Primary Care / Internal Medicine:

• E11.9 Type 2 diabetes (SNOMED 44054006) — most common chronic condition
• I10 Essential hypertension (SNOMED 38341003)
• E78.5 Hyperlipidemia (SNOMED 55822004)
• E66.01 Morbid obesity (SNOMED 238136002)
• J06.9 Upper respiratory infection (SNOMED 54150009)
• N39.0 Urinary tract infection (SNOMED 68566005)

Cardiology:

• I25.10 Coronary artery disease (SNOMED 53741008)
• I50.9 Heart failure (SNOMED 84114007)
• I48.91 Atrial fibrillation (SNOMED 49436004)
• I21.9 Acute MI (SNOMED 57054005)

Pulmonology:

• J44.1 COPD with exacerbation (SNOMED 195951007)
• J45.20 Mild asthma (SNOMED 195967001)
• J18.9 Pneumonia (SNOMED 233604007)
• J96.01 Acute respiratory failure (SNOMED 65710008)

Nephrology:

• N18.1–N18.6 CKD stages 1–5 (SNOMED 431855005 for CKD)
• N17.9 Acute kidney injury (SNOMED 14669001)

Endocrinology:

• E03.9 Hypothyroidism (SNOMED 40930008)
• E05.90 Hyperthyroidism (SNOMED 34486009)
• E11.65 DM with hyperglycemia (SNOMED 609567009)

Mental Health:

• F32.1 Major depression, moderate (SNOMED 73867007)
• F41.1 Generalized anxiety (SNOMED 21897009)
• F10.20 Alcohol use disorder (SNOMED 7200002)
• F17.210 Nicotine dependence (SNOMED 56294008)

Oncology:

• C34.90 Lung cancer (SNOMED 93880001)
• C50.919 Breast cancer (SNOMED 254837009)
• C61 Prostate cancer (SNOMED 399068003)
• C18.9 Colon cancer (SNOMED 93761005)

Orthopedic / Pain:

• M54.5 Low back pain (SNOMED 279039007)
• M17.11 Primary osteoarthritis, knee (SNOMED 239873007)
• S72.001A Hip fracture (SNOMED 5913000)

Pediatric:

• J45.20 Asthma (SNOMED 195967001)
• J30.9 Allergic rhinitis (SNOMED 61582004)
• L20.9 Atopic dermatitis (SNOMED 24079001)
• J20.9 Acute bronchitis (SNOMED 10509002)

Comorbidity Clusters

Generate co-occurring conditions (not random independent diseases):

• Metabolic syndrome: E11.9 T2DM + I10 HTN + E78.5 Hyperlipidemia + E66.01 Obesity
• Cardiovascular cascade: I10 HTN → I25.10 CAD → I50.9 CHF
• CKD progression: N18.1→N18.5, often with HTN and T2DM
• COPD cluster: J44.1 COPD + J18.9 Pneumonia + F17.210 Nicotine dependence
• Mental health: F32.1 Depression + F41.1 GAD (frequently co-occurring)
• Chronic pain: M54.5 Low back pain + G89.29 Chronic pain + F11.20 Opioid use disorder
• Geriatric: Dementia (F03.90) + falls (W19) + incontinence (R32)
• Pediatric atopic triad: J45.20 Asthma + J30.9 Rhinitis + L20.9 Eczema

Clinical Status and Severity

• clinicalStatus (http://terminology.hl7.org/CodeSystem/condition-clinical): active, recurrence, relapse, inactive, remission, resolved.
• verificationStatus (http://terminology.hl7.org/CodeSystem/condition-ver-status): confirmed, unconfirmed, provisional, differential, refuted, entered-in-error.
• severity (http://snomed.info/sct): 24484000 Severe, 6736007 Moderate, 255604002 Mild.

Staging

For stageable conditions, include Condition.stage[]:

• Cancer: TNM staging (stage I–IV) with summary code from SNOMED or AJCC.
• CKD: N18.1 (Stage 1, GFR ≥90) through N18.6 (ESRD, GFR <15).
• Heart failure: NYHA Class I–IV.
• Liver disease: Child-Pugh A/B/C, MELD score.

Body Site

Include Condition.bodySite with SNOMED CT codes when anatomically specific:

• Knee (49076000), Hip (29836001), Lung (39607008), Heart (80891009), Liver (10200004), Kidney (64033007), Brain (12738006).

Evidence

Link Condition.evidence[].detail to supporting resources:

• Observations (lab results confirming diagnosis).
• DiagnosticReports (imaging, pathology).

Onset and Abatement

• Acute conditions: onsetDateTime within days of encounter.
• Chronic conditions: onsetDateTime or onsetAge years before current encounter.
• Resolved conditions: abatementDateTime or abatementString set.
• Use onsetAge for childhood-onset conditions (e.g., Type 1 DM at age 8).

References

• Condition.subject → Reference(Patient/{id}) — required.
• Condition.encounter → Reference(Encounter/{id}) — link to diagnosing encounter.
• Condition.recorder → Reference(Practitioner/{id}) — who recorded it.
• Condition.asserter → Reference(Practitioner/{id} | Patient/{id}) — who asserted it.