People with autism can seem to lack the ability to create emotional bonds and can struggle with interactions with others. Children with autism are often over-excited when in high stimulus environments, which can mimick hyperactivity. Both children with ADHD and children with autism can have a hard time adjusting to change.
People that suffer from hearing impairments can experience problems in social situations and may have underdeveloped communication. They may have a hard time paying attention because of their inability to hear properly. Undiagnosed hearing loss can appear as missing details of conversations, not listening or not paying attention. These symptoms are also common in individuals with ADHD.
Hypothyroidism can create feelings of sadnes or depression. People with ADHD can also suffer from these feelings, especially if depression is a co-existing condition. Hypothyroidism also includes symptoms of inability to concentrate and memory problems. ADHD also includes the symptom inability to concentrate, and forgetfulness can be mistaken for memory loss.
Iron Deficiency in adults causes lethargy, feeling exhausted and irritability. In infants and children, however, the symptoms include irritability, inability to concentrate, impaired cognitive skills and a short attention span. Children with ADHD also show symptoms of inability to concentrate and are distracted easily, mimicking a short attention span.
Lead poisoning, even at low levels, can create a number of problems. Some complications of lead toxicity include mental retardation, decreased school performance, short-term memory problems, inability to concentrate and decreased cognitive function. Many of these symptoms are also seen in children with ADHD.
Intellectual disability, previously known as mental retardation, can appear as emotional immaturity. Some symptoms include limited social skills, school performance issues and needing extra time to learn. Symptoms of mild disability include forgetfulness and the inability to connect consequences with actions.
Hypoglycemia, also called low blood sugar, can cause a number of symptoms similar to ADHD including aggression, hyperactivity, inability to sit still or low concentration levels. In addition, some people also have an adverse reaction to chemicals in food, such as, MSG, red dye, corn syrup or additional additives. These reactions can include anger, agitation, impulsiveness, hyperactivity and lack of concentration.
Some children with mild seizures can experience "absence seizures" lasting only a few seconds. Sometimes these seizures are not even noticeable. After a seizure there can be a period of several hours where someone feels disoriented and confused, causing difficulty following directions or being attentive.
For children with sensory disorder, overstimulation can create symptoms similar to ADHD. They may take risks without understanding the danger, quickly jump from activity to activity, be accident-prone or have difficulty paying attention.
Although people with ADHD notoriously have difficulty sleeping, they may or may not have a sleep disorder. The inability to get a good night’s sleep interferes with many daytime activities. People who lack sleep can have a hard time concentrating, communicating, following directions, and may suffer decreased short-term memory.