Hair loss can be prevented by ensuring that your scalp is moisturised at all times. Hair loss usually occurs when the scalp is dry thus reducing helpful enzymes and secretions that keeps the hair alive to those areas. Also, dandruff doesn't occur when the hair is properly moisturize with essential oils.

More times than not, hair loss is genetic. It would almost certainly occur if it's in the lineage. You can hold it off for some time though by applying creams that rejuvenates the cells around the scalp and taking in enough of vitamin A and Vitamin E which ensures that sebum is always supplied to those areas.

Also, try washing your hair with shampoo as often as possible. It prevents the build of infections.

Another thing is to eat food rich in protein as they help to replenish dead cells around the your scalp.

Lastly, it is advisable to not brush your hair when it's wet. The hair is weakest when wet. It's also advisable not to brush your hair too often as you would be injuring the hair and increase chances of loss.