12/05/2026
When people think about Attention Deficit Hyperactivity Disorder (ADHD), they often think about symptoms such as inattention, forgetfulness, impulsivity, or hyperactivity. However, growing research shows that untreated ADHD can affect far more than concentration alone — it can also have a significant impact on physical health and overall wellbeing.
For many adults living with untreated ADHD, the brain is constantly active. Racing thoughts, chronic overwhelm, emotional dysregulation, restlessness, and difficulty “switching off” can keep the body in a prolonged state of stress. Over time, this can place strain on the nervous system and cardiovascular system.
One of the body’s main stress responses involves the release of cortisol and adrenaline — commonly known as stress hormones. In short bursts, these hormones are helpful and protective. But when stress becomes chronic, as can happen with untreated ADHD, the body may remain in a prolonged “fight or flight” state. This can contribute to increased heart rate, muscle tension, poor sleep, fatigue, headaches, and elevated blood pressure over time.
Research has also linked untreated ADHD with higher rates of burnout, anxiety, sleep disorders, obesity, substance misuse, and cardiovascular risk factors. Difficulties with organisation, routine, emotional regulation, and self-care can make it harder for individuals to maintain healthy habits such as regular exercise, balanced nutrition, hydration, and consistent sleep patterns.
