Bleeding from the gums on brushing or eating is an indication that they are inflamed. This is caused by inadequate removal of bacterial plaque by toothbrush.
You will need to see your dentist or hygienist for removal of the plaque and calcium deposits. Once resolved good oral hygiene should be maintained coupled with regular visits to the hygienist. Flossing tape and/or the use of interproximal brushes may also be necessary.
If your gums are swollen and tender they will bleed when brushing your teeth. You will notice blood when spitting during brushing your teeth.