Hi, I am a student and can't concentrate on my studies for a very long time. Do you know ways to increase it?

Limit distraction. If you are healthy & rested look at how & where you study & see if you can make success more likely. Kitchen table (people wandering thru)bed (might make you sleepy)media on (distracts). Try a place out of the family traffic flow. Limit media to comfort (music).Get a hr timer with an alarm and set for 50min intervals. Study for 50min, relax & enjoy a break & reset as needed.
Find the cause. Kids with allergies have more problems in school than those who don't. Certain nutritional deficiencies can interfere with focus & too much sugar, not enough protein can also interfere. Medical conditions like anemia and hypothyroidism can be involved too.