- unhealthy lifestyle: lack of sleep, stress, Smoking, alcohol abuse, poor nutrition contribute to memory impairment;
- lack of sleep directly affects the processes of assimilation of information, because at night in the brain there are complex biochemical processes that transform short-term memory into long term;
- stress causes the release of blood hormones that stimulate the body to full capacity. Chronic stress comes depletion of all functions and systems, including memory;
- Smoking causes lack of oxygen (hypoxia) of the brain tissue that subsequently leads to distraction;
- alcohol causes atrophy (shrinkage) of the cerebral cortex. In the end a person develops a condition called dementia, which affects not only the memory;
- poor nutrition causes deficiency of vitamins (b, C, E) and amino acids (folic and nicotinic), without which metabolism in the brain.

The cause of the deterioration of memory can be some somatic diseases: diabetes, atherosclerosis, arterial hypertension, hypothyroidism, stroke, neuroinfection, severe disease of liver and kidneys in the stage of decompensation. Craniocerebral trauma also can cause forgetfulness.

Sudden memory loss to the extent that a person does not remember what he did a minute ago, is found in severe mental illness, damaging people over 65 years of Alzheimer's disease.

The slow process of remembering can cause certain medicines, for example antihistamines, first generation ("Suprastin", "Diphenhydramine", "Tavegil", etc.), hypnotics, anti-anxiety and pain pills.

Depression is often observed memory impairment. This is due to a predominance of inhibitory processes in the brain and slowing all body functions. After exiting this state, the memory returns to the original level.