Hi Dear, The lump or swelling could be a mucocoele that is a cystic lesion arising from minor salivary glands...nothing to panic.As per your complain the lump over the lower lip can be due to inflammation as well as HEMATOMA formation because of some minor injury . The hematoma is formed due to injury to the small blood vessels leading to spillage of blood into soft tissues as well as there is release of inflammatory exudate and overgrowth of fibrous tissue and appearrence of inflammatory cells at the site of injury. You should do alternate hot and cold packs over the lump.. Apply Thrombophob gel from outside as it helps in faster dissolution of clot. You can once consult an oral pthologist for evaluated to rule out the nature of lesion as in a few conditions surgical removal can be done. Avoid any cosmetic product for now , because lump can also form due to allergy to cosmetic products . Hope your concern has been resolved. Dr. Harry Maheshwari