Thanks for posting your query.
The formation of lump and bruise after trauma suggests internal bleeding
and hematoma formation which can heal by fibrosis (scarring) and feels numb and hard.
Ideally it should resolve gradually in 4_6 weeks without any intervention if uncomplicated.But if it involves any blood vessel or nerves or other soft tissue
or if infected ( complications) then it needs to be evaluated by a doctor to check for adequate healing.
Pain relief can be achieved temporarily by analgesics, antiinflammatory drugs like ibuprofen, or diclofenac
(which hastens healing), as per prescription of treating physician.
But if lump persists more than 4_6 weeks, please consult your doctor or a general surgeon
for confirmation of diagnosis and further management.
Wishing you good health...
Dr Saurabh Gupta.