For elementary school children – this is normal. In adults that often happens in the case of fatigue, after a long and monotonous work, disease.
If an individual is worried about some problem, he is fully devoting her attention and thereby becoming inattentive to other things happening around him.
But often the patient, trying to gather my thoughts, makes it even worse. He gets tired quickly and this close to exhaustion. A good example of this, students before exams. All night they bison tickets as long as you know what to study next is useless, as it does not get focus on the target material.
Chronic inattention should be identified as soon as possible. This will help simple talk with a specialist or in the form of various tests. It is very important to be able to distinguish normal absent-mindedness from mental illness.
There is a special test that is performed in the detection of low concentration. This is a test Bourdon. It is also called proof-reading test. It can be used for both adults and children. The more people will cope with the task in the test, the better he fared with concentration.
To deal with poor concentration will help proper nutrition, rest, nature walk, aromatherapy. Greatly helps to develop attention meditation and several other exercises.