The Breathing Expert: Mouth Breathing Linked To ADHD, Diabetes & Child Sickness!

Breathing through the nose filters, warms and humidifies air, recaptures moisture, and boosts nitric oxide production up to sixfold, improving circulation and immune defense. Nestor’s Stanford experiment forcing 10 days of mouth breathing rapidly created snoring, sleep apnea, exhaustion and inflammation. Practical steps include consciously closing the mouth during the day, training to nasal-breathe while exercising (even if intensity must drop initially), and using gentle aids at night (e.g., Myotape, chin straps) to keep the mouth shut while maintaining safety.

If a child habitually breathes through an open mouth, snores, or if you can audibly hear them breathing at night, Nestor argues this is ‘cause for alarm’. Research on over 11,000 children found those with sleep-disordered breathing were 50–90% more likely to develop ADHD-like symptoms, hyperactivity, aggression, depression and anxiety. Many researchers he cites claim most so‑called ADHD in kids is sleep-disordered breathing. Parents should film their child sleeping, note mouth posture and sounds, and push pediatricians, ENTs and dentists to assess airway size, nasal obstruction, and breathing habits—not just prescribe stimulants or remove tonsils.

Most people use only ~5–10% of their diaphragm because they sit slumped and breathe shallowly into the upper chest. This forces the heart to work harder, limits gas exchange, and keeps the nervous system in a low-level stress state. Nestor demonstrates simple drills: sitting or standing tall with a relaxed but straight spine, placing hands above the hip bones and feeling them move laterally on inhale, then placing fingers on the upper chest to feel subtle expansion without lifting the shoulders. Practiced daily (and incorporated into workouts), this retrains the diaphragm, improves lung inflation, and supports better posture automatically.

Acute stress (email ‘apnea’, airport queues, arguments) pushes people into sympathetic over-breathing or breath-holding. Nestor suggests two main tools: (1) the ‘physiological sigh’—two quick inhales followed by a long, relaxed exhale—to rapidly reset breathing and calm a spike of stress, and (2) slow nasal breathing with a slightly longer exhale (e.g., 4 seconds in, 6 seconds out or about 5–6 seconds in and out) to strengthen parasympathetic tone, lower heart rate, and often reduce blood pressure by 10–15 points in minutes. The exhale lengthens heart-rate deceleration, signaling safety to the nervous system.

Chronic anxiety, panic, and ‘office stress breathing’ are strongly associated with low CO₂ levels from constant shallow, rapid breathing and frequent breath-holds. Nestor recommends a daily BOLT/control pause test: take a normal breath in, exhale to a neutral end, then hold until you first feel clear discomfort (swallow, diaphragm twitch, urge to breathe), and time it. Most people start around 15 seconds; athletes ~20; those with severe asthma/panic as low as 3–5 seconds. A functional target is ~40 seconds with a calm, unforced first inhale afterwards. Repeating this test and practicing slower nasal breathing and breath holds gradually increases CO₂ tolerance and resilience to stress.