Why are you not able to concentrate:reasons

Our inability to concentrate and focus is accompanied by many factors, this factors cause distraction and that's why we can't focus. However some concentration killers have being identified.


Hunger The brain can't focus without fuel, so skipping meals -- especially breakfast --  is a top concentration killer. Many studies show the negative effects that hunger has on school-aged children and young adults. Research also indicates short-term memory and attention are affected when you rise and shine but do not dine.

Fatigue Tiredness also leads to poor concentration and when this is felt, all that is needed is rest. This will give the brain cells opportunity to re-vitalize itself. 

Stress The inability to cope with the pressure leads to stress.Stress affects the ability to concentrate, many studies have suggested that stress interferes with ability to concentrate.  Learning how to relax, taking regular exercise and adopting good time-management techniques will help limit the stress and get your brain back to normal functioning.

Depression  The National Institute of Mental Health says difficulty concentrating is one of the most common symptoms of depression. When having trouble focusing, also feeling of emptiness, hopeless, or indifferent, you may be linked to depression. In depression, one may experience lack of interest t and pleasure in daily activities, significant weight loss or gain, insomnia or excessive sleeping, lack of energy and can also cause lack of concentration. However, many studies have shown the effectiveness of antidepressant medications.  Also psychotherapy, coping and cognitive-behavioral techniques can also be employed.

Medication Some medications such as those used in treating depression can interfere with concentration.
According to Drs. Bowden and Sinatra in their book The Great Cholesterol Myth, statin drugs, a cholesterol-lowering medications might just be the single worst group of drugs for your brain. Cholesterol is needed to make neurotransmitters — chemicals that brain cells use to communicate with each other. It is necessary for memory, learning, and fast thinking.

Poor Nutrition Low-fat diets can limit concentration and focus because the brain needs certain essential fatty acids.  Vegetables and fruits can give you the essential vitamins (particularly B vitamins and vitamin D) and minerals, including adequate iron, boost that your ability to concentrate and health breakfast will get your brain started and gives it the necessary requirement needed to function properly.

Sources: http://www.webmd.com
              http://www.bettermind.com