• Allergies and sensitivities to food (dairy, grains, peanuts, food dye) and the environment (grass, pollen, animal dander), can affect behavior.

• Exposure to toxins can cause hyperactivity, attention deficits, irritability, and learning problems. Children are more vulnerable to toxins than adults. Toxins include pesticides, gasoline fumes, herbicides, disinfectants, furniture polishes, air fresheners, synthetic rugs and carpets, and beds made of synthetic materials and/or dust-laden homes.

• Hearing and vision problems may cause ADD/ADHD behavior if a child can't see or hear properly -- especially in educational settings.

• Children who are experiencing emotional stress (such as being bullied at school, divorce or death in family, abuse) most often display ADHD behavior.  Emotionally-stressed children can experience sleeping problems, sadness, and they develop physical symptoms, especially if they think those symptoms will keep them home from school.  Often they can't concentrate in class, partly because they are worried and partly because they are suffering from sleep deprivation.

• Learning Style or Learning Disabilities are often the cause of inattention and acting-out behavior.  Children with a diagnosis of ADHD are typically kinesthetic learners and have difficulty with sitting at a desk doing pencil-and-paper work.  When children think of themselves as 'stupid', 'lazy', or 'slow' and are seen as such, they often will be disruptive in school (e.g., class clown, bullying others).

• CAPD (Central Auditory processing Disorder) will sometimes occur in children who have had a history of ear infections and/or PE tubes.  Symptoms include distractibility, inability to follow a set of verbal instructions, and 'spacing out'.

• Sensory Integration Dysfunction is thought to be the inefficient neurological processing of information received through the senses, causing problems with learning, development, and behavior.  These children are over-sensitive or under-sensitive dealing in touch, taste, smell, sound, or sight.

• Tourette syndrome is a rare but disruptive condition.  It involves multiple tics (small, repetitive muscle movements), usually facial tics with grimacing and blinking.  Tics may also occur in the shoulders and arms.  This is usually accompanied by loud vocalizations, which may include grunts or noises, or uncontrollable (compulsive) use of obscenities or short phrases.  The tics are worse during emotional stress and are absent during sleep.  The cause is unknown.  It occurs most often in boys, and may begin around age 7 or 8 or not until the child is in his or her late teens or early twenties.  It may, at times, run in families.  This disorder can be mistaken for not being able to sit still or impulsive behavior.

• Infestations of Candida albicans (yeast infection) cause hyperactivity in children.  Most children who do suffer from Candida infestations have some underlying problem frequently an immune disorder, or a disorder affecting carbohydrate metabolism that alters blood sugar levels.  Candida infestations are now thought to be a common condition throughout the population.

• Intestinal parasites rob the body of needed nutrients which in turn affects behavior.

• Streptococcus bacteria, better known as 'strep', can cause rheumatic fever and a movement disorder known as Sydenham's chorea if left untreated.  Recurrent infections can also lead to a group of symptoms collectively known as PANDAS (Pediatric autoimmune neuropsychiatric disorders).  Some symptoms of PANDAS include obsessive-compulsive behavior, Tourette syndrome, hyperactivity, cognitive problems, and fidgeting.

• Hypoglycemia (low blood sugar) can stem from thyroid disorders, liver or pancreatic problems, adrenal gland abnormalities, or insufficient diet.

• Hyper-thyroidism or hypo-thyroidism is an imbalance in metabolism that occurs from an overproduction or underproduction of thyroid hormones.  This imbalance may cause a variety of behaviors and may affect all body functions.

• Some mild forms of genetic disorders can go unnoticed in children and display some of the same symptoms of ADHD.   Mild forms of Turner's syndrome, sickle-cell anemia, and Fragile X syndrome are some examples.  Almost any genetic disorder can cause hyperactivity or other behavior problems, even if the disorder isn't normally linked to such problems.  Many genetic diseases disrupt brain functions directly, through a variety of paths.  A simple blood test can rule out genetic disorders.

• A commonly overlooked cause of ADHD behavior is the absence seizure.  During an absence seizure, the brain's normal activity shuts down.  The child stares blankly, sometimes rotates his eyes upward, and occasionally blinks or jerks repetitively, he drops objects from his hand, and there may be some mild involuntary movements known as automatisms.  The attack lasts for a few seconds and then it is over as rapidly as it begins.  If these attacks occur dozens of times each day, they can interfere with a child's school performance and be confused by parents and teachers with daydreaming.

• Post-traumatic subclinical seizure disorder causes episodic temper explosions.  These fits of temper come out of the blue for no reason.  Some of these seizures can be too subtle to detect without a twenty-four-hour electroencephalogram (EEG).

• Head injuries, such as post-concussion syndrome, have symptoms that include irritability, mood swings, memory problems, depression, and sleeping problems.

• Some spinal problems can cause ADHD behavior because, if the spine is not connected to the brain properly, nerves from the spinal cord can give the brain all of signals at once making a child rambunctious and full of energy.

• Some drugs (both prescription and illegal) can cause the brain to atrophy, leading to disturbed cognition and behavior.  If your child routinely takes prescription or over-the-counter medications for asthma, hay fever, allergies, headaches, or any other condition, consider the possibility that the drugs are causing or contributing to behavior problems.

• Intentionally or unintentionally sniffing materials such as modeling glue or other household products.

Other possible causes of ADHD behavior are:  malnutrition or improper diet (e.g., B-vitamin deficiency, iron deficiency); lack of exercise; lack of sleep; viral or bacterial infections; early-onset diabetes; heart disease; brain cysts; early-stage brain tumors.