Should You Ask Your Doctor About Blood Tests for ADHD Evaluation?

PostedSeptember 11, 2025

UpdatedSeptember 11, 2025

ByMy Patient Advice

Author: Harriet Winslow, BSc | Reviewed by: Dr. Rebecca Fernandez, MBBS

While ADHD is primarily diagnosed through behavioural assessments, including blood tests in ADHD evaluation can be helpful in ruling out other medical conditions that may cause similar symptoms. Fatigue, inattention, and mood changes can sometimes result from underlying health issues, so discussing blood tests in ADHD evaluation with your doctor can be a sensible step.

These tests might include checks for iron levels, as low iron can affect cognitive performance and energy. B12 tests can identify deficiencies linked to concentration problems and memory issues. Hormone checks, particularly for thyroid function, can also be important, as hormonal imbalances may mimic or worsen ADHD-like symptoms. Including such tests supports medical rule-outs, ensuring that treatment focuses on the correct underlying cause.

How It Helps

Ruling Out Other Causes

Incorporating blood tests in ADHD evaluation helps determine whether symptoms are due to ADHD or to treatable conditions such as low iron, B12 deficiency, or thyroid problems.

Supporting a Complete Health Picture

By combining behavioural assessments with hormone checks and other medical investigations, doctors can develop a clearer understanding of the individual’s overall health. This supports better decision-making and ensures that ADHD treatment is not addressing symptoms caused by unrelated issues.

In summary, requesting blood tests in ADHD evaluation can be a valuable step, helping to confirm the diagnosis and guide a more effective, tailored treatment plan.

Visit providers like ADHD Certify for personal consultations and expert advice tailored to your needs.

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to Rule-outs for other conditions.

Harriet Winslow, BSc

Author

Harriet Winslow is a clinical psychologist with a Bachelor’s in Clinical Psychology and extensive experience in behaviour therapy and developmental disorders. She has worked with children and adolescents with ADHD, autism spectrum disorder (ASD), learning disabilities, and behavioural challenges, providing individual and group therapy using evidence-based approaches such as CBT and DBT. Dr. Winslow has developed and implemented personalised treatment plans, conducted formal and informal assessments, and delivered crisis intervention for clients in need of urgent mental health care. Her expertise spans assessment, treatment planning, and behavioural intervention for both neurodevelopmental and mental health conditions.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy.

Dr. Rebecca Fernandez, MBBS

Reviewer

Dr. Rebecca Fernandez is a UK-trained physician with an MBBS and experience in general surgery, cardiology, internal medicine, gynecology, intensive care, and emergency medicine. She has managed critically ill patients, stabilised acute trauma cases, and provided comprehensive inpatient and outpatient care. In psychiatry, Dr. Fernandez has worked with psychotic, mood, anxiety, and substance use disorders, applying evidence-based approaches such as CBT, ACT, and mindfulness-based therapies. Her skills span patient assessment, treatment planning, and the integration of digital health solutions to support mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewer's privacy.