I51.9 - Heart disease, unspecified

Version 2023
ICD-10:I51.9
Short Description:Heart disease, unspecified
Long Description:Heart disease, unspecified
Status: Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Diseases of the circulatory system (I00–I99)
    • Other forms of heart disease (I30-I5A)
      • Complications and ill-defined descriptions of heart disease (I51)

I51.9 is a billable ICD-10 code used to specify a medical diagnosis of heart disease, unspecified. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.

Unspecified diagnosis codes like I51.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Clinical Information

Index to Diseases and Injuries References

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for this diagnosis code are found in the injuries and diseases index:

Convert to ICD-9 Code

Source ICD-10 CodeTarget ICD-9 Code
I51.9429.9 - Heart disease NOS
Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education


Heart Diseases

What is heart disease?

Heart disease is a general term that includes many types of heart problems. It's also called cardiovascular disease, which means heart and blood vessel disease.

Heart disease is the leading cause of death in the United States, but there are ways to prevent and manage many types of heart disease.

What are the types of heart disease?

There are many different types of heart disease. Some you may be born with, called congenital heart disease. Other types develop during your lifetime.

Coronary artery disease (also called coronary heart disease) is the most common type of heart disease. It happens slowly over time when a sticky substance called plaque builds up in the arteries that supply your heart muscle with blood. The plaque narrows or blocks blood flow to the heart muscle and can lead to other heart problems:

Other types of heart diseases may affect your heart valves or heart muscle (cardiomyopathy).

What causes heart diseases?

The causes of heart disease depend on the type of disease. Some possible causes include lifestyle, genetics, infections, medicines, and other diseases.

Who is more likely to develop heart diseases?

There are many different factors that can make you more likely to develop heart disease. Some of these factors you can change, but others you cannot.

What are the symptoms of heart disease?

Your symptoms will depend on the type of heart disease you have. You may not have symptoms at first. In some cases, you may not know you have heart disease until you have a complication such as a heart attack.

How are heart diseases diagnosed?

To find out if you have heart disease, your health care provider will:

In some cases, your provider may refer you to a cardiologist (a doctor who specializes in heart diseases) for tests, diagnosis, and care.

What are the treatments for heart disease?

Treatment plans for heart disease depend on the type of heart disease you have, how serious your symptoms are, and what other health conditions you have. Possible treatments may include:

Can heart diseases be prevented?

You may be able to lower your risk of certain heart diseases by making heart-healthy lifestyle changes and managing any other medical conditions you have.

NIH: National Heart, Lung, and Blood Institute


[Learn More in MedlinePlus]

Risk Factors for Type 2 Diabetes

Risk factors for developing type 2 diabetes include overweight, lack of physical activity, history of other diseases, age, race, and ethnicity.
[Learn More in MedlinePlus]

Code History