How to Document and Code for Hypertension Using ICD-10 Codes

by | Mar 7, 2019 | Medical Coding News, Resources | 0 comments

Hypertension (HTN), also known as high blood pressure (HBP) is a common condition in which the blood pressure in the arteries is constantly elevated. Generally, blood pressure is determined both by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. The more blood your heart pumps and the narrower your arteries, the higher your blood pressure. The long-term force of the blood against your artery walls is high enough to cause severe health complications like heart disease, stroke or even death. The medical guidelines issued by the American Heart Association (AHA) 2017 define hypertension as blood pressure that is higher than 130 over 80 millimeters of mercury (mmHg). Without early diagnosis and proper treatment, HBP can lead to life-threatening conditions. Physicians treating this condition can depend on reliable medical billing companies for accurate and timely claim filing for appropriate reimbursement.

Reports from the American Heart Association (AHA, 2018 statistics) say that an estimated 103 million U.S. adults have high blood pressure – which is nearly half of all adults in the United States. Acute causes of high blood pressure include stress, but it can happen on its own or from an underlying condition, like kidney disease. In most cases, people with HBP don’t experience any specific signs or symptoms, even if blood pressure readings reach dangerously high levels. On the other hand, some people may experience minor symptoms like headache, shortness of breath or nosebleeds. Often, these signs and symptoms aren’t specific and don’t occur until blood pressure has reached a severe or life-threatening stage. Potential risk factors that may increase the chances of having hypertension include – age, family history, increased body weight, alcohol and tobacco use, physical inactivity, a salt-rich diet (involving processed and fatty foods) and presence of certain health conditions like cardiovascular disease, diabetes, chronic kidney disease and high cholesterol levels.

Types of Hypertension (HTN)

Hypertension can be Primary (essential) hypertension and secondary hypertension. These two types of hypertension account for about 90% of all hypertension cases. For primary/essential hypertension – there is no identifiable cause of high blood pressure and the condition tends to develop gradually over many years. Caused by an underlying condition, secondary hypertension tends to appear suddenly and cause higher blood pressure than the primary type. Diseases that might be a cause of hypertension include – chronic kidney disease, sleep apnea, adrenal gland tumors, alcohol addiction, thyroid dysfunction, congenital defects and use of certain medication. In this type of hypertension, once the root cause is treated, blood pressure usually returns to normal or is significantly lowered.

However, there are several types of HTN that are less common, but are not less important. These include – malignant hypertension, resistant hypertension, pulmonary hypertension, isolated systolic hypertension, Pseudo-hypertension and White coat hypertension. This means it is important to know how to monitor hypertension based on its type.

How to Diagnose and Treat HTN?

As part of initial diagnosis, physicians will conduct a detailed physical examination and review the patient’s previous medical history. The blood pressure is measured using a pressure-measuring gauge. Blood pressure readings, given in millimeters of mercury (mm Hg), have two numbers. The first, or upper, number measures the pressure in the arteries when the heart beats (systolic pressure). The second, or lower, number measures the pressure in the arteries between beats (diastolic pressure). Blood pressure measurements fall into four general categories –

  • Normal blood pressure – if it’s below 120/80 mm Hg
  • Elevated blood pressure – if it’s a systolic pressure ranging from 120 to 129 mm Hg and a diastolic pressure below 80 mm Hg
  • Stage 1 hypertension – if it’s a systolic pressure ranging from 130 to 139 mm Hg or a diastolic pressure ranging from 80 to 89 mm Hg.
  • Stage 2 hypertension – if it’s a systolic pressure of 140 mm Hg or higher or a diastolic pressure of 90 mm Hg or higher

Both numbers in a blood pressure reading are important. However after 50 years of age, the systolic reading is even more significant. Physicians will generally take 2-3 readings each at three or separate appointments before making a final diagnosis. This is because blood pressure normally varies throughout the day, and it may be elevated during visits to the doctor.

Physicians may recommend a 24-hour blood pressure monitoring test called “ambulatory blood pressure monitoring” which measures the blood pressure at regular intervals over a 24-hour period and provides a more accurate picture of blood pressure changes over an average day and night. In addition, physicians may also recommend other routine tests like – urine test (urinalysis), blood tests, cholesterol test, electrocardiogram (that measures the heart’s electrical activity) and echocardiogram to check for more signs of heart disease.

Treatment for this condition involves a combination of medications and changes in lifestyle habits. Medications include – Angiotensin-converting enzyme (ACE) inhibitors, Calcium channel blockers, Alpha-beta blockers and Renin inhibitors. Incorporating key lifestyle changes like eating a heart-healthy diet (with less salt and fatty foods), limiting the amount of alcohol, doing regular physical activity and maintaining a healthy body weight can help reduce blood pressure.

Medicare Coverage and Coding Guidelines

If you are diagnosed with high blood pressure, Medicare Part B covers all medically necessary doctor visits and outpatient tests and procedures to treat and manage your condition. Medicare Part B may also pay for weight loss counseling sessions and smoking cessation sessions if performed by a qualified professional who accepts Medicare assignment.

Cardiology medical billing and coding is challenging, as it involves numerous rules related to reporting the procedure accurately. Cardiologists or other specialists who treat hypertension and other associated conditions must use the relevant ICD-10 codes to bill for the procedure.

The ICD-10 codes for diagnosing hypertension and other related conditions include –

I10 – Primary (essential) hypertension

I15 – Secondary hypertension

  • I15.0 – Renovascular hypertension
  • I15.1 – Hypertension secondary to other renal disorders
  • I15.2 – Hypertension secondary to endocrine disorders
  • I15.8 – Other secondary hypertension
  • I15.9 – Secondary hypertension, unspecified

Hypertension and Associated Conditions

If a patient with hypertension is confirmed to have co-morbid heart and/or kidney disease, it should be reported using ICD-10 codes in the following manner –

Hypertension and Heart Disease

I11 – Hypertensive heart disease

  • I11.0 – Hypertensive heart disease with heart failure
  • I11.9 – Hypertensive heart disease without heart failure

Hypertension and Chronic Kidney Disease

If the patient has hypertension and then develops chronic kidney disease, ICD-10 will consider that condition as hypertensive chronic kidney disease. However, if the chronic kidney disease occurs first and then the combination, their codes fall under the secondary hypertension codes.

I12 – Hypertensive chronic kidney disease

  • I12.0 – Hypertensive chronic kidney disease with stage 5 chronic kidney disease or end stage renal disease
  • I12.9 – Hypertensive chronic kidney disease with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease

Both these codes require an additional N18 code to specify the stage of kidney disease.

  • N18.1 – Chronic kidney disease, stage 1
  • N18.2 – Chronic kidney disease, stage 2 (mild)
  • N18.3 – Chronic kidney disease, stage 3 (moderate)
  • N18.4 – Chronic kidney disease, stage 4 (severe)
  • N18.5 – Chronic kidney disease, stage 5
  • N18.6 – End-stage renal disease
  • N18.9 – Chronic kidney disease, unspecified

Hypertension, Heart Disease and Chronic Kidney Disease

The ICD-10 codes for the three-disease combination (if the patient has all the three conditions, hypertension, heart disease and chronic kidney disease) are classified according to the degree of chronic kidney disease rather than the presence or absence of heart failure.

I13 – Hypertensive heart and chronic kidney disease

  • I13.0 – Hypertensive heart and chronic kidney disease with heart failure and stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease
  • I13.1 – Hypertensive heart and chronic kidney disease without heart failure
    • I13.10 – Hypertensive heart and chronic kidney disease without heart failure, with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease
    • I13.11 – Hypertensive heart and chronic kidney disease without heart failure, with stage 5 chronic kidney disease, or end stage renal disease
  • I13.2 – Hypertensive heart and chronic kidney disease with heart failure and with stage 5 chronic kidney disease, or end stage renal disease

Just as the two-disease combination codes, the above codes also require additional codes from the N18 series to specify the stage of kidney disease.

Coding for Nicotine Dependence

An additional ICD-10 code is required for all hypertension codes if the patient uses tobacco currently or had used it earlier. The codes for nicotine use include –

F17 – Nicotine dependence

  • F17.2 – Nicotine dependence
    • F17.20 – Nicotine dependence, unspecified
    • F17.21 – Nicotine dependence, cigarettes
    • F17.22 – Nicotine dependence, chewing tobacco
    • F17.29 – Nicotine dependence, other tobacco product

Other Hypertension Codes

I27.0 – Primary pulmonary hypertension
I27.2 – Other secondary pulmonary hypertension

  • I27.20 – Pulmonary hypertension, unspecified
  • I27.21 – Secondary pulmonary arterial hypertension
  • I27.22 – Pulmonary hypertension due to left heart disease
  • I27.23 – Pulmonary hypertension due to lung diseases and hypoxia
  • I27.24 – Chronic thromboembolic pulmonary hypertension
  • I27.29 – Other secondary pulmonary hypertension

High blood pressure (HBP) generally develops over many years, and can affect nearly everyone. The higher your blood pressure and the longer it goes uncontrolled, the greater the damage. Uncontrolled high blood pressure can lead to complications including heart attack or stroke, aneurysm, dementia, trouble with memory and metabolic syndrome. However, a right combination of medications along with significant lifestyle changes can help people effectively control and prevent blood pressure in the long run.

Medical coding for hypertensive disorders can be complex, as there are several categories of codes. Outsourcing medical billing tasks to a reliable and established medical billing and coding company (that provides the services of AAPC-certified coding specialists) can help with correct and timely claims submissions.