Radiology Coding Alert

A quick peek at the ICD-10-CM index will demonstrate just how many forms a condition like hypertension can take. It’s for this reason, in addition to the plethora of associated ICD-10-CM guidelines, that it’s one of the more challenging diagnosis coding concepts to grasp among coders.

Properly identifying hypertension diagnoses in your reports, and subsequently how they play into other complications or manifestations documented, is paramount if you want to get the coding mechanics down pat.

Read on for answers to six critical questions surrounding hypertension diagnoses.

First, Understand Normal Versus Hypertension Readings

Question 1: What is considered normal blood pressure versus hypertension (high blood pressure)?

Answer: Normal blood pressure is 120/80mm Hg at rest, said instructor Sharon Jane Oliver, CPC, CDEO, CPMA, CRC, at the recent 2021 HEALTHCON session “The Disease of Hypertension.” On the other hand, high blood pressure (hypertension) is usually documented at 100/60-140/90 mm HG.

The physician usually diagnoses hypertension with a series of tests and has the patient keep a diary of daily pressure readings.

“By the time high blood pressure is documented, the damage may have already been done,” Oliver added. “It’s known as the ‘silent killer.’”

See Different Hypertension Stages

Question 2: What are the different stages of hypertension?

Answer: Oliver provided the following chart to show the different stages of hypertension. However, she added that there are no specific ICD-10-CM codes to identify these different stages.

Decipher Essential and Malignant Hypertension

Question 3: Can you tell me more about essential versus malignant hypertension? Which ICD-10-CM codes should I report for these conditions?

Answer: You actually have one ICD-10-CM code to cover essential and malignant hypertension. If you look under I10 (Essential (primary) hypertension), you will see that this code includes high blood pressure, arterial, benign, essential, malignant, primary, and systemic hypertension.

Essential hypertension defined: Essential hypertension occurs in 10-15 percent of white adults and 20-30 percent of black adults, according to Oliver. The typical onset of essential hypertension is between ages 25-50. It’s uncommon for essential hypertension to occur before age 20.

Malignant hypertension defined: About 1 percent of patient have malignant hypertension. When a patient has malignant hypertension, he requires urgent hospitalization to prevent a stroke or brain hemorrhage. Signs and symptoms of malignant hypertension include headache, blurred vision, and dyspnea, Oliver said.

Zero in on Hypertension Causes

Question 4: What causes hypertension?

Answer: “Hypertension happens when the arterioles narrow,” Oliver said. “An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries. When the body is functioning as it should, the arterioles help ensure that the blood pressure remains within normal, healthy limits. The importance of the arterioles is that they are the primary site of both resistance and regulation of blood pressure.”

Patient Has Hypertensive Heart Disease? Do This

Question 5: If a patient has hypertensive heart disease, how should I report this diagnosis on my claim?

Answer: If your radiologist documents that the patient has hypertension along with heart conditions classified to categories I50.- (Heart failure), I51.4 (Myocarditis, unspecified)-I51.7 (Cardiomegaly), I51.89 (Other ill-defined heart diseases), or I51.9 (Heart disease, unspecified), you should report the appropriate code from category I11- (Hypertensive heart disease), according to the ICD-10 guidelines. If the patient has heart failure, you should also report an additional code from category I50.- to identify the exact heart failure type. However, if your cardiologist documents that the heart conditions I50.-, I51.4-I51.7, I51.89, and I51.9 are not related to the patient’s hypertension, you would code those conditions separately and sequence according to the circumstances of the admission or encounter.

Include CKD Stage When Reporting Hypertensive CKD

Question 6: If the patient has hypertensive chronic kidney disease (CKD), how should I report this diagnosis on my claim?

Answer: If your radiologist diagnoses the patient with both hypertension and a condition that falls under category N18- (Chronic kidney disease (CKD)), you should report the appropriate code from category I12- (Hypertensive chronic kidney disease), per the guidelines.

Caution: You can report the CKD as hypertensive even if the radiologist does not specifically document the CKD as related to the patient’s hypertension because ICD-10 directs coders to assume the causal relationship in this case.

Additionally, when you report a code from category I12-, you should also report a secondary code from category N18- to indicate which stage of CKD the patient has. And, if the patient has acute renal failure along with the hypertensive CKD, you must also report the appropriate code for the acute renal failure.

Editor’s note: Want more great info like this? You can now register for the upcoming 2021 HCON regional conferences: https://www.aapc.com/medical-coding-education/conferences/. Visit www.aapc.com for more info.