Memory loss at the age of 40 may be caused by neurasthenia, excessive stress and intracranial lesions. 1. neurasthenia: if the 40-year-old middle-aged people long-term neurasthenia, may affect sleep, cause fatigue, but also may harm the brain cells, there may be memory loss. 2. Excessive pressure: 40-year-old middle-aged people have a heavier burden, life will be more stressful, the patient’s pressure if you can not get timely release, may appear memory loss performance. 3. Intracranial lesions: Intracranial lesions, such as intracranial space-occupying lesions, may also lead to memory loss in middle-aged 40-year-olds. Intracranial space-occupying lesions is a general term for a group of diseases that occupy a certain space location within the cranial cavity, such as cysts and tumors. Surgery is performed on the advice of a doctor if necessary. There are many other causes of memory loss at the age of 40, if memory loss occurs, it is recommended that patients go to the hospital in a timely manner, under the guidance of a physician to clarify the cause of the disease, and give targeted treatment.