Home Health ICD-9/ICD-10 Alert

Question: The physician documents that our patient's hypertension is "uncontrolled." Should I use a malignant hypertension ICD-9 code? How would my coding differ if the doctor simply states "hypertension" or "history of hypertension"?

Pennsylvania Subscriber

Answer: "Uncontrolled" and "malignant" don't have the same meaning. Hypertension that is uncontrolled is not necessarily considered malignant.

The type of hypertension your patient has is what should drive your hypertension code selection, not the term "uncontrolled." Uncontrolled hypertension may be coded with the fourth digit of "1" for benign or"'9" if not specified as malignant or benign. So you would use 401.9 (Essential hypertension; unspecified) for your patient rather than 401.0 (Essential hypertension; malignant).

Keep in mind: Hypertension, commonly referred to as "high blood pressure" or "HTN," is a medical condition in which the blood pressure is chronically elevated. Malignant hypertension is a complication of hypertension characterized by very elevated blood pressure, and organ damage in the eyes, brain, lung and/or kidneys. It includes a sustained diastolic pressure of 120 or above, despite treatment.

Before you can list a malignant hypertension diagnosis, the physician must specifically document that the patient has malignant hypertension. Unfortunately, physicians often use words that mean one thing in ICD-9 but something else to them. When the physician is vague about the type of hypertension, you should ask him what he means, have him clarify it in the medical record, and then assign the ICD-9 code accordingly.

ICD-10 update: In ICD-10, you will no longer need to specify whether primary hypertension is malignant, benign, or unspecified. As a result, the hypertension table, found in the Alphabetic Index in ICD-9, isn't included in ICD-10. All primary hypertension is reported with the same code: I10 (Essential [primary] hypertension).