None or many
A scary thing about gum disease
: it is 'silent'--there may not be obvious bleeding you are aware of, teeth loosening, or swollen gums
(= signs and symptoms of gum disease) until too late.
This is why a dentist measures your gum pockets to gauge how healthy or diseased your gums are. When a probe is used to measure gums, healthy gums do not (1) hurt, or (2) bleed, or (3) measure deeper than 3mm.