2008 ICD-9-CM Volume 1 Diagnosis Codes Home > Injury And Poisoning 800-999 > Complications Of Surgical And Medical Care, Not Elsewhere Classified 996-999 > Complications Affecting Specified Body System Not Elsewhere Classified 997.* > 2008 ICD-9-CM Diagnosis 997.91 Complications affecting other specified body systems not elsewhere classified hypertension  On October 1, 2008 the 2009 ICD-9-CM codes came into effect. Therefore, this code may be out of date. The 2009 version of ICD-9-CM 997.91 can be accessed here. Abnormally high blood pressure. Pathological increase in blood pressure. Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more. 997.91 is a specific code that can be used to specify a diagnosis 997.91 contains 1 index entry View the ICD-9-CM Volume 1 997.* hierarchy ICD9Data's sister site ProcedureCodes.com launches with the 2008/09 CPT® codes - read more on the ICD9Data.com blog. 997.91 excludes: Essential hypertension (401. 0-401.9) Index entries containing 997.91: Hypertension, hypertensive (arterial) (arteriolar) (crisis) (degeneration) (disease) (essential) (fluctuating) (idiopathic) (intermittent) (labile) (low renin) (orthostatic) (paroxysmal) (primary) (systemic) (uncontrolled) (vascular) 401.0 401.1 401.9 postoperative 997.91