About how long does it take for a knot under a bruise to heal?

Get the knot out.: The knot under the bruise can take as little as a week and over a year to completely resolve. There are occasions that the knot will always be there, only smaller. This depends on the size, location and type of injury that caused it. In the initial stages of the injury, ice can be applied to minimize bleeding. After 48 hours, heat application can speed the dissolving of the lump.