# What Is the Morbidity Rate?

Factors and How It Differs From Mortality Rate

## What Is the Morbidity Rate?

Morbidity rate refers to the rate at which a disease or illness occurs in a population. This can be used to determine the health of a population and its health care needs. Illnesses can range from acute conditions to chronic, long-lasting conditions.

Morbidity rates are also used in actuarial professions—such as health insurance, life insurance, and [long-term care insurance](https://www.investopedia.com/terms/l/ltcinsurance.asp)—to determine the [premiums](https://www.investopedia.com/terms/p/premium.asp) to charge customers. This rate shouldn't be confused with the mortality rate, another metric that highlights the frequency of death in a given population.

### Key Takeaways

*   A morbidity rate tracks how acute and chronic diseases infect a population
*   Morbidity rates can be used to determine the overall health of a population
*   By using a morbidity rate, the health care needs of a population can be determined
*   These rates are also used in actuarial industries, such as insurance
*   Insurers use morbidity rates to develop policies for coverage, determine premiums, and set benefits for insurance claims

## Understanding Morbidity Rate

According to the Centers for Disease Control and Prevention, morbidity refers to "any departure, subjective or objective, from a state of physiological or psychological well-being." In simpler terms, morbidity is the word used to describe the instance of a disease or illness, including acute and chronic conditions.

An acute condition may be caused by a virus and doesn't last very long, like a cold. Chronic conditions are more demanding on a population as they tend to be last longer, cost more to treat, and may need multiple layers of physical or mental health care.

They include such diseases as:

*   Diabetes
*   Cancer
*   Heart disease
*   Kidney disease
*   HIV/AIDS
*   Depression

Because morbidity rates measure the frequency at which illness and disease occur in a population, they are used in various ways in the public and [private sectors](https://www.investopedia.com/terms/p/private-sector.asp). For instance, governments may use morbidity rates and other health statistics to research health and [health care](https://www.investopedia.com/terms/h/health_care_sector.asp). This includes costs, the success and failures of government programs, and the quality of health care systems.

## Morbidity Rates and Insurance

Morbidity rates are also helpful in many sectors of the [financial sector](https://www.investopedia.com/terms/f/financial_sector.asp). For example, [insurance](https://www.investopedia.com/terms/i/insurance.asp) companies use morbidity rates to predict the likelihood that an insured will contract or develop certain diseases. This helps them develop competitively-priced insurance policies in the industry for health insurance, life insurance, and coverage for long-term care.

The ability to accurately estimate morbidity rates for various diseases is helpful for insurers to set aside sufficient funds to cover benefits and claims for their customers. This data is also used in part to establish prices for the premiums that the insurance companies charge.

Other main factors in pricing premiums are mortality rates, [operating expenses](https://www.investopedia.com/terms/o/operating_expense.asp), investment [returns](https://www.investopedia.com/terms/r/return.asp), and regulations. For example. many insurance companies base their pricing of group insurance products on an expected payout of benefits. A company uses its assumptions for mortality, morbidity, interest, expenses, and persistence to price its products.

> **Important**
>
> Don't confuse morbidity rates with mortality rates, which measure how many deaths occur in a specific population.

## Morbidity Rate vs. Mortality Rate

People often confuse morbidity (rates) with mortality (rates). Although they sound the same, they are different. While morbidity rates refer to the frequency of disease and illness in a certain area, the [mortality](https://www.investopedia.com/terms/m/mortality-table.asp) rate is used to describe the frequency of death in a population. Mortality is the direct result of a condition or illness. The mortality rate is determined by dividing the number of deaths that result from an illness by the total population.

Mortality rates can be [divided into different categories](https://www.investopedia.com/wealthy-americans-and-mortality-11716348) based on various measures, including infant mortality and cause-related mortality.

## Other Rates for Diseases

The proportion of initial disease cases to a population is an [incidence rate](https://www.investopedia.com/terms/i/incidence-rate.asp). In contrast, the proportion of initial and existing disease cases in a population is known as the prevalence rate.

For example, 50,000 new cases of heart disease developed in a city with a population of five million in a single year, while the incidence of morbidity rate is 1%. If 250,000 people already suffer from heart disease in the city, the prevalence rate increases from 5% to 6%.

## What Is the Definition of Morbidity?

The definition of morbidity as used by the medical community often refers to having a disease, a chronic health problem, or the amount of disease and illness within a population.

## What Is the Difference Between Morbidity and Mortality?

The term morbidity refers to the rate at which an illness or disease occurs in a population. Mortality rate is the rate of death in a population.  

## What Is the Difference Between Morbidity Rate and Mortality Rate?

A morbidity rate tracks data on illness and disease within a population, while a mortality rate tracks the number of deaths from illness or disease within a population. Both morbidity and mortality rates are statistics used to measure the overall health of a population among other metrics.  

## How Can You Calculate Morbidity Rate?

Morbidity incidence rates are calculated by dividing the number of new cases of illness or disease within a specific period of time by the number of individuals in the population.

## The Bottom Line

Understanding the difference between the definition of morbidity rate and mortality rate can help you better understand statistics related to illness and death. While the two terms sound the same, they apply to different metrics. A morbidity rate is the rate at which an illness or disease occurs withing a population, while a mortality rate is the rate of death.

> **Article Sources**
>
> 1.  Centers for Disease Control and Prevention. "[Epidemiology Glossary](https://www.cdc.gov/reproductivehealth/data_stats/glossary.html)," click on "M."
>     
> 2.  U.S. Centers for Medicare & Medicaid Services. "[Chronic Conditions](https://www.cms.gov/Research-Statistics-Data-and-Systems/Statistics-Trends-and-Reports/Chronic-Conditions/CC_Main)."
>     
> 3.  Jose Bien R. Hernandez and Peggy Y. Kim. “[Epidemiology Morbidity and Mortality](https://www.ncbi.nlm.nih.gov/books/NBK547668/).” StatsPearls Publishing.