“Brain fog” is not a medical condition.The term is used to certain symptoms that convey that ability to think is affected. That is what you are trying to convey. Yes Stress can cause such symptoms. Like you said that you are preparing for JEE which is a stressful event. Try to take 7-8 hours for the sleep. Go for a regular healthy food. Do some exercises regularly. Go for meditation or Yoga for the relaxation of the mind and body. Have you undergone similar symptoms in the past? What coping skills you used? There are so many other questions are to be asked, A detailed medical and other history is to be taken.

No dear. It's seems u are going through a stress and showing impaired attention. But for proper diagnosis all detail history needed.

Hello, I would like to know a detailed history so that we can discuss about the best treatment available for you. Thanks

It is a symptom of depression kindly consult for evaluation

Sir, A detailed history is required to diagnose Brain Fog Most of times it turns out to be depression or just anxiety episodes However , good news is there is treatment for all the conditions Please visit your nearest psychiatrist