Memory loss can occur for different reasons... Aging - called dementia. Alzheimer’s disease, alcoholism, infections and of course head trauma, especially if it's repeated head trauma.
There are two major categories of memory:
Short-term memory includes remembering people names that you just met, or remembering things you just did or placed recently.
Long-term memory includes things we did years ago, old time friend, coworkers, kids names or relatives.
Recommended Changes to improve or fight memory loss.
Mind Exercise that include reading, memorizing things, puzzles or crosswords.
Physical exercise correlates with better mental functions because it improves blood circulation in your body.
Absolutely try to avoid Alcohol, mainly because alcohol is damaging brain cells.
Try not to stress, reduce stress every-way possible. Practice yoga, try different relaxation techniques or meditation.