Hypertension and Hypertensive, primary, secondary and combination
Coding for hypertension and hypertensive (without complications) is easier in ICD-10-CM because there is no ?benign? vs. ?malignant? issue ? there is only essential hypertension, indicated by code I10 Essential (primary) hypertension.
Hypertension has a limited number of ICD-10 codes ?
- Only nine codes for primary hypertension and
- Five codes for secondary hypertension. This makes the task of coding hypertension relatively simple ,at least compared to some of the other ICD-10 complexities.
Combination codes come into play, in cases when hypertension affects a body system. The code set is as follows:
- Hypertensive heart diseasewith category I11,
- Hypertensive chronic kidney diseasewith category I12 and
- Hypertensive heart and chronic kidney diseasewith category I13.
In ICD-10, the hypertensive disease codes exclude several conditions: Hypertension complicating pregnancy, neonatal hypertension, primary pulmonary hypertension, primary and secondary hypertension involving vessels of the brain or the eye and postprocedural hypertension. In addition, one needs to be able to differentiate the capital ?I? from the number ?1″ in the “Diseases Of Circulatory system”. The hypertension codes range from I10 to I15 , there is no I14 and each series has its own peculiarities.
Hypertension and Hypertensive Heart Disease: I11
Hypertensive heart disease is the No. 1 cause of death associated with high blood pressure. It refers to a group of disorders that includes heart failure, ischemic heart disease, hypertensive heart disease, and left ventricular hypertrophy. If the patient has hypertensive heart disease, the physician must make the connection with the conditions for the combination code to be assigned. Documentation must state ?heart failure due to hypertension? or imply a causal relationship, ?hypertensive heart failure,? to assign a code from category I11.
In ICD-10, there are two base codes:
- I11.0, Hypertensive heart disease with heart failure
- I11.9, Hypertensive heart disease without heart failure
In situations, where the patient has all three conditions present ? hypertension, heart disease, and chronic kidney disease (CKD) ? the guidelines state the connection must be made for the heart disease and hypertension, but not for the CKD and hypertension.
Essential (primary) hypertension: I10
Coding for Essential Hypertension in ICD-10 is easy, that is I10, Essential (primary) hypertension, as it uses only a single code for individuals who meet criteria for hypertension and do not have co-morbid heart or kidney disease. Whereas in ICD-9, essential hypertension was coded using 401.0 (malignant), 401.1 (benign), or 401.9 (unspecified).
Hypertension and chronic kidney disease: I12
If the patient has hypertension and develops chronic kidney disease, ICD-10 presumes a cause and effect relationship and classifies the condition as hypertensive chronic kidney disease. However, if the chronic kidney disease was diagnosed first, then the combination falls into the secondary hypertension codes.
Specifying the stage of the Chronic Kidney Disease is same in ICD10 like ICD9 . Only that ICD-10 differentiates stage 5 from end-stage renal disease by the need for chronic dialysis.
ICD-10 requires first using an I12 code for the combined diagnosis of hypertension and chronic kidney disease:
- I12.0, Hypertensive chronic kidney disease with stage 5 chronic kidney disease or endstage renal disease,
- I12.9, Hypertensive chronic kidney disease with stage 1 through 4 chronic kidney disease or unspecified chronic kidney disease.
These two codes require an additional N18 code to identify the stage of kidney disease, with documentation typically referencing the most recent eGFR :
- N18.1, Chronic kidney disease, stage 1,
- N18.2, Chronic kidney disease, stage 2 (mild),
- N18.3, Chronic kidney disease, stage 3 (moderate),
- N18.4, Chronic kidney disease, stage 4 (severe),
- N18.5, Chronic kidney disease, stage 5,
- N18.6, End-stage renal disease, ? N18.9, Chronic kidney disease, unspecified.
Hypertension, hypertensive heart disease, and chronic kidney disease: I13
If the patient has all three conditions (hypertension, heart disease, and chronic kidney disease), then one needs to document the relationship between the hypertension and heart disease but assume the causal relationship between hypertension and chronic kidney disease.
Important point to be noted for the three-disease combination is, they are numerically arranged by the degree of chronic kidney disease rather than the presence or absence of heart failure:
- I13.0, Hypertensive heart and chronic kidney disease with heart failure and with stage 1 through 4 chronic kidney disease, or unspecified chronic kidney disease,
- I13.10, Hypertensive heart and chronic kidney disease without heart failure with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease, ?
I13.11, Hypertensive heart and chronic kidney disease without heart failure with stage 5 chronic kidney disease, or end-stage renal disease,
- I13.2, Hypertensive heart and chronic kidney disease with heart failure and with stage 5 chronic kidney disease, or end-stage renal disease.
All of the three-combination codes require additional coding from the N18 series to identify the stage of kidney disease. The three-combination codes that include heart failure also require additional coding from the I50 series to specify the type and sharpness of the failure.
Nicotine or Tobacco use or exposure in individuals with hypertensive diseases
If the patient is a current or former tobacco or nicotine user, all of the hypertension codes require an additional ICD-10 which is found in chapter “Mental and behavioral disorders due to psychoactive substance use”. For Eg: The codes from I10 to I15 requireS the use of an additional code from the following codes mentioned below:
- F17, Nicotine dependence,
- F17.20, Unspecified,
- F17.21, Cigarettes,
- F17.22, Chewing tobacco,
- F17.29, Other tobacco product.
And each of these four categories requires a sixth character:
- 0, uncomplicated,
- 1, in remission,
- 3, with withdrawal,
- 8, with other specified nicotine-induced disorder.