ADLs are the basic self-care tasks you need to survive, like bathing and eating. IADLs are the more complex tasks you need to live independently in a community, like managing money and preparing meals. The distinction matters because these two categories decline at different rates, get assessed with different tools, and signal different things about a person’s health.
The Six Basic ADLs
Basic activities of daily living are the fundamental physical tasks a person performs to take care of their own body. There are six, originally defined by a scale called the Katz Index that is still widely used today:
- Bathing: showering, grooming, maintaining dental hygiene, and caring for hair and nails
- Dressing: selecting appropriate clothes and putting them on
- Toileting: getting to and from the toilet, using it, and cleaning up afterward
- Transferring: moving from one position to another, such as getting out of bed into a chair
- Continence: controlling bladder and bowel function
- Feeding: bringing food from a plate to your mouth and eating it
These tasks are primarily physical. They don’t require much planning or decision-making, but they do require enough strength, coordination, and mobility to move your body through basic routines. A person who cannot perform one or more of these without help has what clinicians call an “ADL impairment.”
The Eight Standard IADLs
Instrumental activities of daily living are a step up in complexity. They’re the skills that let someone function independently in a household and a community, not just care for their body. The traditional list includes eight categories:
- Using the telephone: looking up numbers, dialing, answering calls
- Shopping: getting to a store and selecting what you need
- Preparing food: planning and cooking meals
- Housekeeping: maintaining a reasonably clean living space
- Doing laundry: washing, drying, and putting away clothes
- Managing transportation: driving, arranging rides, or using public transit
- Taking medications: managing the right doses at the right times
- Handling finances: paying bills, managing a bank account, budgeting
Each of these tasks involves planning, sequencing, and judgment. Cooking a meal, for instance, requires deciding what to make, gathering ingredients, following steps in order, and monitoring timing. Paying a bill requires understanding due dates, navigating a payment system, and keeping track of account balances. These are cognitive tasks wrapped inside everyday routines.
Physical Demands vs. Cognitive Demands
The core distinction between ADLs and IADLs comes down to what they ask of the brain versus the body. Research examining the demands of each type found that managing money, self-administering medications, using the telephone, and preparing meals require significantly more cognitive effort. Walking, transferring between surfaces, and climbing stairs are primarily physical.
This doesn’t mean ADLs are brainless or IADLs don’t involve the body. Getting dressed requires some problem-solving (choosing weather-appropriate clothes, managing buttons). Grocery shopping requires the physical ability to walk through a store. But the balance tilts clearly: ADLs lean physical, IADLs lean cognitive. That difference has real implications for how and when each set of abilities breaks down.
Why IADLs Decline First
In conditions that affect cognition, like dementia, IADL abilities almost always deteriorate before basic ADLs. The typical sequence is loss of initiative first, then loss of planning ability, then loss of basic self-care skills. This pattern makes sense: if your brain is struggling with executive function (the ability to plan, organize, and carry out multi-step tasks), you’ll lose the ability to manage finances and cook meals long before you lose the ability to feed yourself or get dressed.
This is why IADL impairment often serves as an early warning sign. A person who starts missing bill payments, stops cooking, or can’t manage their medications may still look fine in terms of basic self-care. Family members frequently notice IADL problems first: the refrigerator is empty, mail is piling up, or prescriptions aren’t being refilled. By the time someone needs help with bathing or dressing, the condition has typically progressed further.
In contrast, conditions that are primarily physical, like a hip fracture or severe arthritis, tend to affect ADLs first. Someone recovering from hip surgery may struggle to get out of bed or use the bathroom but can still manage their finances from a phone.
How Each Category Is Assessed
Healthcare providers use specific tools to measure ADL and IADL function, and the two scales work differently.
The Katz Index of Independence in Activities of Daily Living scores each of the six basic ADLs with a simple yes or no: can the person do this task independently, or can’t they? The total score ranges from 0 to 6. A score of 6 means full function. A score of 3 to 5 indicates moderate impairment. A score of 2 or less signals severe functional impairment.
The Lawton Instrumental Activities of Daily Living Scale covers the eight IADL categories. For each task, a person chooses the description that best matches their highest functional level, scored as 1 (can do it) or 0 (cannot). The summary score ranges from 0 to 8 for women and 0 to 5 for men. That gender difference is a historical artifact: when the scale was developed in the 1960s, tasks like cooking, housekeeping, and laundry were excluded from the men’s version because many men had never performed them. Modern clinical practice often scores all eight for everyone.
These assessments get used in a variety of settings. Hospitals use them to decide whether a patient can safely go home. Nursing facilities use them to determine the level of care someone needs. Insurance companies and government programs use them to establish eligibility for benefits, since many long-term care policies define a benefit trigger as needing help with two or more ADLs.
What ADL Impairment Means for Health
Losing the ability to perform ADLs independently is one of the strongest predictors of poor health outcomes in older adults. A large population-based study of people aged 80 and older found striking differences in mortality rates. Among those aged 80 to 89, people with ADL disability had a mortality rate of 80.4%, compared to 57.6% for those without disability. In the 90 to 99 age group, the gap narrowed but persisted: 95.4% versus 82.6%.
These numbers don’t mean ADL impairment directly causes death. Rather, the inability to care for yourself reflects the overall burden of disease, frailty, and physical decline. It’s a reliable signal that the body’s systems are failing in ways that carry serious risk. This is one reason healthcare providers track ADL and IADL function so closely: changes in these abilities often reveal health problems before other symptoms become obvious.
Digital IADLs: A Modern Expansion
The original IADL categories were defined decades ago, and daily life has changed. Shopping, banking, communication, and information retrieval have all migrated to digital platforms. Researchers have proposed that digital activities of daily living aren’t a separate category but rather the modern way many traditional IADLs are now performed.
An updated framework of digital IADLs includes categories like online communication, digital information retrieval, managing healthcare through patient portals, controlling smart home devices, online shopping, digital financial management, and even remote work tasks like teleconferencing. Gaming was also included as a common leisure activity that supports social connection and mental wellbeing.
This expansion matters practically. An older adult who could once pay bills by writing checks may struggle when their bank shifts to an online-only system. Someone who managed social connections through phone calls may become isolated as friends and family shift to text messaging or video calls. Assessing a person’s ability to navigate digital tools is increasingly relevant to understanding whether they can truly live independently, especially as more essential services move online.
Rehabilitation and Support
Because ADLs and IADLs involve different skills, the approaches to restoring or supporting them differ too. For basic ADLs, occupational therapy often focuses on rebuilding physical ability through task-oriented training, balance exercises, and repetitive practice of specific movements. Mirror therapy and mental imagery (visualizing a movement before performing it) have strong evidence for improving ADL performance, particularly after stroke.
IADL support tends to lean more on compensatory strategies: simplifying tasks, using reminders and checklists, setting up automatic bill payments, or arranging grocery delivery services. The goal shifts from restoring the ability to finding workarounds that preserve independence despite the limitation.
Newer approaches blend both. Virtual reality training can simulate real-world tasks like cooking or navigating a store, allowing people to practice in a safe environment. These technologies enable personalized programs and continuous monitoring of progress, making rehabilitation more targeted than traditional methods alone.