Hello, Absentmindedness commonly occurs due to sleep-deprivation, substance abuse, developing mental illness like bipolar disorder, delirium, drug withdrawal, tiredness, etc. To avoid absent mindedness, you should avoid stress and keep yourself relaxed. Train yourself to focus on a particular task and project. Complete the task/project before engaging yourself in anything else. Do not take many work at a time. Take food in time , stay well hydrated. Cause of mental distraction is commonly lack of interest, many people are easily distracted with smartphones, internet, gossips, hunger, multi-tasking and autism, etc. To prevent distraction, patients are recommended to take distraction therapy that includes cognitive behavior therapy, they are taught to set short term goals, sleep well. Avoid addictions if any. You are suggested to get clinically examined by a GP. Get blood workouts done, get CBC, urinalysis and all necessary imaging tests done to detect any developing pathology. You will be treated accordingly. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician