Diseases of the circulatory system
ICD-10 Code: I10
Essential (Primary) Hypertension
Essential hypertension (I10) is persistently elevated blood pressure of unknown cause. This is the most commonly used hypertension code when no underlying cause is identified.
Clinical Information
Essential hypertension, also called primary hypertension, is high blood pressure that doesn't have a known secondary cause. It accounts for 90-95% of all hypertension cases.
**Key Characteristics:**
- Systolic BP ≥130 mmHg or Diastolic BP ≥80 mmHg (AHA 2017 guidelines)
- Often asymptomatic (silent killer)
- Major risk factor for heart disease, stroke, and kidney disease
- Strongly associated with age, obesity, family history, and lifestyle factors
Coding Guidelines
- 1I10 is used for all types of hypertension without documented complications
- 2Do not use additional codes for 'benign' or 'malignant' hypertension (removed in ICD-10)
- 3Code separately any associated conditions (e.g., chronic kidney disease)
- 4Use I11.x if hypertensive heart disease is present
- 5Use I12.x if hypertensive chronic kidney disease is present
- 6Use I13.x if both heart and kidney disease are present
Common Uses
- Routine hypertension monitoring and medication management
- Annual physical exams with documented hypertension
- Blood pressure follow-up visits
- Medication adjustments for antihypertensives
- Uncomplicated high blood pressure
Related ICD-10 Codes
I11.0Hypertensive heart disease with heart failure
I12.9Hypertensive chronic kidney disease without heart failure
I13.0Hypertensive heart and CKD with heart failure
O10.011Pre-existing essential hypertension complicating pregnancy
Documentation Requirements
- Document blood pressure readings (systolic/diastolic)
- Note hypertension diagnosis in problem list
- Include current antihypertensive medications
- Document control status (controlled, uncontrolled, inadequate control)
- Note any target organ damage if present
Real-World Coding Examples
Patient presents for HTN follow-up. BP 142/88. On Lisinopril 20mg daily. No complications. → I10
65-year-old with history of essential hypertension for medication refill. BP controlled at 128/78. → I10
Annual wellness exam. Hypertension on three medications, no heart or kidney disease. → I10
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