What does ADL stand for in medical terms?

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In medical terms, ADL means activities of daily living. Generally speaking, this refers to self-care activities such as mobility, personal hygiene, dressing, and self-feeding. 

A person’s ability or inability to perform these ADLs is commonly used as a measurement of functional status. It is most commonly applied to individuals with injuries, disabilities or the elderly in order to identify and address their need for care.  

The concept of ADLs was originally proposed by Dr. Sidney Katz in the 1950s. Today, the concept of ADLs is increasingly being implemented in medical care and research throughout the world. 

Since the concept was conceived, additional activities have been included to expand its use and relevancy. In general, one can separate between basic and instrumental ADLs.

Basic activities of daily living (ADLs)

The basic ADLs originate from the pioneer of the concept, Sidney Katz. They were derived from studying patients with different conditions in a nursing home and how they affected their functional abilities. They include: 

  • Bathing and showering
  • Personal hygiene and grooming (hair)
  • Dressing
  • Toilet hygiene (getting to the toilet, cleaning oneself, and getting back up)
  • Functional mobility (ability to walk, get in and out of bed, and get into and out of a chair)
  • Self-feeding

Most of the basic ADLs are things most people do when they get up in the morning and get ready for the day.

This is very intuitive as the inability to perform these activities is what prevent the sick and elderly to properly care for themselves. 

Not at the basic ADLs are created equally. There is a stage/severity hierarchy that was observed when the concept was developed. 

As an individual loses functional ability due to sickness or old age, the earliest loss function is often hygiene.

Later, if/as the functional ability decreases further, the functions such as toilet use and locomotion are lost.

Finally, the loss of self-feeding indicates late/severe loss of function.

The basic ADLs form criteria used in the Katz Index of Independence in Activities of Daily Living. It is used to detect problems in performing activities of daily living which enables health care workers to plan care accordingly.

Instrumental activities of daily living (IADLs)

Instrumental activities of daily living (IADLs) include more advanced activities. They are not necessary for basic functioning but are required in order for an individual to live independently in a community. They include:

  • Cleaning and maintaining the house
  • Managing money
  • Moving within the community
  • Preparing meals
  • Shopping for groceries and necessities
  • Taking prescribed medications
  • Using the telephone or other forms of communication
  • Doing laundry

The ability to live independently has been shown to be associated with a higher quality of life. Because of this, the deterioration of one’s ability to perform instrumental ADLs can have a significant impact on an individual’s life.

A deterioration in the ability to perform IADLs can be related to disabilities, sickness or old age. Because of this, an evaluation of a person’s ability to perform IADLs is often used to assess if an individual can continue to live in their own home without additional assistance.

The IADLs require a higher degree of cognitive function (brain function) compared to the basic ADLs.

Many will suffer from cognitive impairment as they grow older (dementia, Alzheimer’s disease). Eventually, this loss of cognition can result is a decreased ability to perform IADLs which decreases their ability to live independently.

Because of this, testing for IADLs might indicate cognitive impairment due to dementia or other conditions associated with cognitive impairment. 

Who uses ADL assessments?

ADL assessments are typically performed by physicians or other health care workers to determine if a person needs any assistance in their daily activities/life.

The most common use is to determine if the elderly are in need of home assistance, assisted living, or nursing home care.

Once a need for assistance in daily activities has been uncovered, ADL assessments can also be performed routinely to track an individual’s progression or the effectiveness of any assistance provided.

This is important in order to determine whether older adults can continue to safely live at home or are in need of an increased level of care/assistance.

Measuring and tracking ADLs can also be applied to other individuals with disabilities, injuries or sickness that decrease their ability to perform ADLs, independent from age.  

Another common use is among occupational therapists.

They use ADL assessments to identify a loss or lack of skill (due to sickness or disability), after which they can work with that individual to teach and rebuild the skills required to maintain, regain or increase that person’s independence in all Activities of Daily Living.

Similarly, physical therapists use ADL assessments to tailor exercises that assist patients in maintaining and gaining independence in ADLs.

Finally, Long-term care insurance companies also use ADL assessments as they often provide benefits based on the policyholder’s ability to perform ADLs without needing assistance.

Common ADL assessment tools

There are many different ADL assessment tools. Some consider basic ADLs, while others assess IADLs. Many are developed as a general assessment of the elderly, while others are created for the assessment of individuals with specific conditions.

Most ADL assessment tools score a test subject in a given number of criteria/categories. The lower one’s score, the higher their dependence level, and conversely, a higher score indicates greater independence.

Katz Index of Independence in Activities of Daily Living

Developed by the pioneer of the concept of ADL, Dr. Sidney Katz and first published in 1963. It ranks an individual’s ability to perform the six basic ADLs.

Test subjects are scored yes(1)/no(0) for independence in each of the six functions. A score of 6 indicates the full function, 4 indicates moderate impairment, and 2 or less indicates severe functional impairment. 

The assessment is most useful when applied to older adults in a variety of care settings. Here it enables health care providers to identify and track care needs and apply appropriate care.

While effective, there are some significant limitations. It assesses the basic activities of daily living and does not assess more advanced activities.

Also, while it is sensitive to changes in declining health status, it is limited in its ability to measure small increments of change. 

Lawton-Brody Instrumental Activities of Daily Living scale

Published in 1969, The Lawton Instrumental Activities of Daily Living Scale can be used to assess independent living skills.

Subjects are scored in their ability to perform eight IADLs. Due to historical gender roles, it might be appropriate for women to be scored on all areas while excluding the areas of food preparation, housekeeping, laundering for men to avoid gender bias.

Clients are scored 1 or 0 according to their highest level of functioning in each category. A summary score ranges from 0 (low function, dependent) to 8 (high function, independent) for women and 0 through 5 for men.

The assessment is intended to be used among older adults and can be used in both community or hospital settings. Unlike the Katz assessment, it is not useful for institutionalized older adults.


There are several different assessment tools available. One is the Bristol Activities of Daily Living Scale which has a higher focus on cognitive/memory impairment.

There are also assessment tools that are a part of model programs such as the Roper-Logan-Tierney model of nursing is widely applied in the UK and the Program of All-Inclusive Care for the Elderly (PACE) which is common in the US. 

There are also many individual assessments that have been developed in the domain of disability. These often aim to capture the level of disability and functional recovery in performing basic ADLs.

An example is the Functional Independence Measure, designed for assessment across a wide range of disabilities.

Another is the Spinal Cord Independence Measure which is designed to evaluate participants with disabilities due to spinal injuries.


  1. Wiener, Joshua M., et al. “Measuring the Activities of Daily Living: Comparisons Across National Surveys.” ASPE, The Brookings Institution, U.S. Department of Health and Human Services, 21 Feb. 2017, https://aspe.hhs.gov/basic-report/measuring-activities-daily-living-comparisons-across-national-surveys
  2. Turan, Ebru PhD; Yanardag, Mehmet PhD; Aras, Ozgen PhD. “Topics in Geriatric Rehabilitation”: July/September 2012 – Volume 28 – Issue 3 – p 201–207. doi: 10.1097/TGR.0b013e31825eb924.https://journals.lww.com/topicsingeriatricrehabilitation/Abstract/2012/07000/Functional_Independence,_Quality_of_Life,_and.10.aspx
  3. Carmona-Torres, Juan Manuel et al. “Disability for basic and instrumental activities of daily living in older individuals.” PloS one vol. 14,7 e0220157. 26 Jul. 2019, doi:10.1371/journal.pone.0220157. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6660130/