Specific code 2014 ICD-9-CM Diagnosis Code 401.9
Unspecified essential hypertension
  • Billable Code
  • Short description: Hypertension NOS.
  • ICD-9-CM 401.9 will be replaced by an equivalent ICD-10-CM code (or codes) when the United States transitions from ICD-9-CM to ICD-10-CM on October 1, 2015.
  • ICD-9-CM 401.9 is a billable medical code that can be used to specify a diagnosis on a reimbursement claim.
Disease Synonyms
  • Essential HTN
  • Essential hypertension
  • Good hypertension control
  • Htn
  • HTN (Hypertension)
  • HTN, uncontrolled
  • Hypertension
  • Hypertension (high blood pressure)
  • Hypertension (high blood pressure), uncontrolled
  • Hypertension (high blood pressure), well controlled
  • Hypertension, uncontrolled
  • Hypertension, well controlled
  • Hypertensive disorder
  • Hypertensive disorder, systemic arterial
  • Hypertensive emergency
  • Hypertensive urgency
  • Uncontrolled hypertension
Clinical Information
  • Hypertension occurring without preexisting renal disease or known organic cause.
Convert to ICD-10-CM: 401.9 converts approximately to:
  • 2014 ICD-10-CM I10 Essential (primary) hypertension
ICD-9-CM Volume 2 Index entries containing back-references to 401.9:
  • Blood
    • pressure
      • decreased, due to shock following injury 958.4
      • fluctuating 796.4
      • high (see also Hypertension) 401.9
        • borderline 796.2
        • incidental reading (isolated) (nonspecific), without diagnosis of hypertension 796.2
      • low (see also Hypotension) 458.9
        • incidental reading (isolated) (nonspecific), without diagnosis of hypotension 796.3
  • Disease, diseased - see also Syndrome
    • Huchard's (continued arterial hypertension) 401.9
    • hypertensive (see also Hypertension) 401.9
  • Elevation
    • blood pressure (see also Hypertension) 401.9
      • reading (incidental) (isolated) (nonspecific), no diagnosis of hypertension 796.2
  • High
    • artery (arterial) tension (see also Hypertension) 401.9
      • without diagnosis of hypertension 796.2
    • blood pressure (see also Hypertension) 401.9
      • borderline 796.2
      • incidental reading (isolated) (nonspecific), no diagnosis of hypertension 796.2
  • Huchard's disease (continued arterial hypertension) 401.9
  • Hyperpiesia (see also Hypertension) 401.9
  • Hyperpiesis (see also Hypertension) 401.9
  • Tension
    • arterial, high (see also Hypertension) 401.9
      • without diagnosis of hypertension 796.2
ICD-9-CM codes are used in medical billing and coding to describe diseases, injuries, symptoms and conditions. ICD-9-CM 401.9 is one of thousands of ICD-9-CM codes used in healthcare. Although ICD-9-CM and CPT codes are largely numeric, they differ in that CPT codes describe medical procedures and services. Can't find a code? Start at the root of ICD-9-CM, check the 2014 ICD-9-CM Index or use the search engine at the top of this page to lookup any code.