What types of data are available in UK Biobank?

Overview of UK Biobank Data

UK Biobank holds a wide range of health-related data on approximately 500,000 participants, collected over time through assessment centre visits, online questionnaires, and ongoing linkage to health records. A high-level introduction to the types of data available can be found on the UK Biobank about our data website page. For more detailed information on individual variables, the UK Biobank Data Showcase is the primary resource, listing all available data fields along with supporting documentation.

Exploring the UK Biobank Data Showcase

The Data Showcase can be freely explored and is the main entry point for understanding what data are available. For each data field, which is the basic unit of data in UK Biobank (representing a result or measurement), the Showcase provides:

A Data tab showing graphical and/or tabular distribution of the data
Notes describing how the data were collected and processed
A Resources tab containing questionnaires, protocols, and explanatory documents

Additional guidance on navigating and interpreting the Showcase is available in the UK Biobank Showcase User Guide and the Understanding UK Biobank pages.

Guidance on accessing data is provided in the Data Access Guide.

Assessment Visits

UK Biobank data collected at multiple time points are referred to as instances . An instance represents a specific visit or other data-collection wave for a given data field. If the same data was collected on multiple instances, this can be seen in the 'Instances' tab on showcase. For many fields the instance corresponds to the assessment visit:

Instance 0: Baseline assessment (500,000 participants; 2006–2010)

Instance 1: First repeat assessment (20,000 participants; 2012–2013)

Instance 2: Imaging visit (100,000 participants; 2014-present)

Instance 3: Repeat imaging visit (20,000 participants; 2019-present)

Many variables are measured at more than one instance, enabling longitudinal analyses of change over time.

Types of Data

The data below was collected at the UK Biobank assessment centres as part of one or more of the instance visits:

Background and Sociodemographic Factors

Age, sex, ethnicity
Education, employment, income indicators
Household characteristics
Family history of disease

Lifestyle and Environmental Factors

Smoking and alcohol use
Diet and physical activity
Sleep
Occupational exposures

Health and Medical History (please see further linkage healthcare data below)

Self-reported diagnoses and conditions
Medication use

Cognitive Function

A range of computer-based cognitive tests were administered, in which participants reaction time, numeric memory and fluid intelligence (among other attributes) were assessed. to read about all the different types of tests conducted, please see Category 100026 .

Physical and Functional Measures

Multiple physical measures were taken of participants, including assessing their blood pressure and lung function, as well as the function of their hearing and vision. Examples of other physical and functional measures taken include:

ECG
Grip strength

Biological Samples

Samples collected include blood, urine, and saliva, with many derived laboratory measures available. Please note that we typically only approve access to the raw UK Biobank samples for research groups who will perform an assay on all or a significant number of participants.

Blood measures include:

Blood cell counts
Clinical biochemistry
Infectious disease markers
NMR metabolomics
Telomere length
Urine and saliva samples are available for selected assays

Location and Environmental Data

UK Biobank environmental data captures aspects of participants’ local environment, recognising their importance for health research.

Available data include:

Residential air and noise pollution
Greenspace and coastal proximity
Urban characteristics (UK Biobank Urban Morphometric Platform)

Imaging Assessment Visits

The UK Biobank Imaging Study launched in 2014, with repeat imaging beginning in 2019. By mid-2025, the target of imaging 100,000 participants was achieved.

Imaging modalities include:

Brain MRI
Cardiac MRI
Body MRI
DEXA scans
Carotid ultrasound
Optical Coherence Tomography (OCT)

Imaging data and derived measures are described in detail in the dedicated imaging documentation: https://www.ukbiobank.ac.uk/about-our-data/types-of-data/imaging-data/ https://community.ukbiobank.ac.uk/hc/en-gb/articles/24618819821981-Imaging-Data

In the Showcase, imaging variables are grouped into brain, cardiac, body, and eye imaging categories

Online Follow-up Questionnaires

In addition to assessment centre visits, UK Biobank collects data through online questionnaires completed at various time points after recruitment.

Topics include:

Diet and nutrition (including 24-hour dietary recall)
Mental health
Pain
Occupational history and work environment
Cognitive function
Digestive health

Online questionnaire data differ from assessment centre data in that they are collected remotely, occur at different times, and are not completed by all participants.

Full question wording, timing, and supporting materials are available in the Resources tab for each questionnaire in the Data Showcase, see Category 100089

Physical Activity Monitor Data

Objective physical activity data were collected using a wrist-worn accelerometer, worn continuously for seven days. Physical activity data has been collected for around 100,000 participants, with seasonal repeat measurements also conducted in a subset of these participants. Available variables include acceleration averages, intensity distributions, wear time, calibration metrics, and raw accelerometer statistics. See Category 1008 . These data complement self-reported physical activity measures reported in Category 100054 .

Health-Related Record Linkage

UK Biobank data are continuously linked to national health records, providing long-term follow-up without additional participant visits. Health linked datasets include:

Death registrations
Cancer registrations
Hospital admissions
Primary care data (subset)
COVID-19 testing, hospitalisation, and outcomes

These are described in detail in the Health-related outcomes article.

Biomarker Data

Blood samples collected at baseline and the first repeat assessment have been used to generate a wide range of biomarkers. Please see the following links for further information:

https://www.ukbiobank.ac.uk/about-our-data/types-of-data/biomarker-data/ https://community.ukbiobank.ac.uk/hc/en-gb/articles/15467071866781-Biomarker-data

Available biomarkers include:

Clinical biochemistry
Blood cell counts
Infectious disease markers
Metabolomics biomarkers
Telomere length

Genomics Data

UK Biobank provides large-scale genomic resources linked to the full range of phenotypic, imaging, and outcome data

Available datasets include:

Genome-wide genotyping (~850,000 directly measured variants; >90 million imputed variants)
Whole-exome sequencing (WES), covering protein-coding regions
Whole-genome sequencing (WGS), covering the entire nuclear and mitochondrial genome

Derived and Returned Data

In addition to primary data collection, UK Biobank provides: