Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition that affects thinking, behavior, and daily functioning. It’s most commonly diagnosed in childhood, though symptoms can persist into adulthood. There are three primary types of ADHD: inattentive, hyperactive-impulsive, and combined.

There is no single test to diagnose ADHD. Instead, healthcare providers use a comprehensive process involving medical history, physical exams, and behavioral and educational evaluations.

Types of ADHD

  • Inattentive ADHD: Characterized by distractibility, forgetfulness, and lack of attention to detail.

  • Hyperactive-Impulsive ADHD: Marked by restlessness, impulsive behavior, and difficulty sitting still.

  • Combined ADHD: A mix of both inattentive and hyperactive-impulsive symptoms. This is the most common form.

Who Diagnoses ADHD?

ADHD is diagnosed by a healthcare provider, which may include a pediatrician, primary care doctor, psychologist, or behavioral specialist. Diagnosis in children often involves input from parents, teachers, and other adults familiar with the child’s behavior.

Diagnosing ADHD in Adults

ADHD in adults—especially women—is often diagnosed later in life. Historically, most research focused on boys, so symptoms in adults may have been overlooked or misinterpreted. Adults may experience different or more subtle symptoms, making diagnosis more complex.

Medical History Review

Providers start by gathering a detailed medical history, including:

  • Current symptoms observed at home or school

  • Prenatal exposures (e.g., tobacco, alcohol, drugs)

  • Birth complications or infections

  • History of head trauma or frequent ear infections

  • Family history of ADHD or similar symptoms

Since ADHD is known to run in families, providers may ask about relatives with similar experiences.

Understanding School Performance

To assess how ADHD impacts education, providers may ask:

  • Has a teacher or caregiver reported learning issues?

  • Are emotions or behaviors different at home versus school?

  • Is the child easily distracted when doing homework or chores?

  • Are there ongoing emotional or behavioral challenges?

Physical Examination

A physical exam helps rule out other causes of symptoms. This exam may include:

  • Measuring vital signs (e.g., heart rate, temperature)

  • Checking height, weight, and head circumference

  • Screening vision and hearing

  • Observing motor coordination and communication behaviors

Developmental and Behavioral Evaluation

Providers may assess:

  • How the child interacts with caregivers, teachers, or peers

  • Frequency of school absences

  • Developmental milestones (e.g., first words, sentences, multilingual skills)

Behavioral evaluations also involve:

  • Determining when symptoms began

  • Duration and consistency of symptoms

  • Whether symptoms affect daily tasks at school or home

  • Use of behavior rating scales completed by parents and teachers

Common Behavior Rating Scales

These tools help providers measure ADHD symptoms:

  • Conners Comprehensive Behavior Rating Scales: Ages 4–5

  • ADHD Rating Scale-IV: Ages 4–5

  • ADHD Rating Scale-5: Ages 5–17

  • Vanderbilt Assessment Scales: Ages 4 and up

Educational Evaluation

Teachers or aides may complete evaluations that include:

  • ADHD-specific behavior rating scales

  • Report cards and schoolwork samples

  • Observations of behavior, learning patterns, and social interaction

To be effective, educators must have worked with the child consistently for at least 4–6 months.

DSM-5 Diagnostic Criteria

Healthcare providers use the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) to diagnose ADHD. To qualify:

  • Children under 17 must have six or more symptoms

  • Individuals 17 and older must have five or more symptoms

  • Symptoms must last at least six months

  • Must appear in more than one setting (e.g., school and home)

  • Must begin before age 12

  • Must interfere with school, work, or social life

Inattentive ADHD Symptoms

To meet diagnostic criteria, the following symptoms must be present:

  • Making careless mistakes, lack of attention to detail

  • Trouble focusing during activities or play

  • Not listening when spoken to directly

  • Incomplete assignments or ignoring instructions

  • Avoiding tasks that require sustained attention

  • Difficulty organizing activities

  • Frequently losing things

  • Easily distracted

  • Often forgetful

Hyperactive-Impulsive ADHD Symptoms

Symptoms may include:

  • Fidgeting or squirming while seated

  • Frequently leaving seat in inappropriate situations

  • Feeling restless

  • Difficulty playing quietly

  • Excessive talking

  • Blurting out answers prematurely

  • Difficulty waiting their turn

  • Interrupting others or intruding on activities

Combined ADHD

Some individuals show an equal number of symptoms from both categories. In this case, the diagnosis is Combined ADHD, the most common type in the U.S.

Screening for Other Conditions

ADHD symptoms may overlap with other developmental or emotional conditions, known as comorbidities, including:

  • Learning disabilities

  • Language disorders

  • Autism spectrum disorder (ASD)

  • Sleep disorders

  • Depression or anxiety

  • Oppositional defiant disorder

  • Conduct disorder

Healthcare providers may run additional evaluations to rule out these conditions and ensure an accurate diagnosis.

Final Thoughts

If your child—or you—are showing signs of ADHD, early evaluation is essential. While ADHD symptoms can be frustrating, diagnosis and treatment can greatly improve daily life and overall well-being. Speak with a healthcare provider to better understand what’s causing the symptoms and how to address them effectively.