Hi and welcome,
Lump or swelling in the neck area can be due to many reasons ,
.enlargement of salivary gland
due to inflammation,
. viral or bacterial infection with lymph node enlargement can form lumps in neck ,
. Infected tooth may drain abscess in the spaces of neck leading to lump formation.
.bening or malignant growth
exact diagnosis can be made only after clinical examination and radiographic evaluation by a doctor.
If the lump is painful , mean time i would suggest you to start witha antibiotic course of Augmentin
625mg with analgesics like aceclofenac serratiopeptidase
twice daily for 3 to 5 days till the symptoms subside.
i hope this helps ,