Swollen thumbnail with pus inside is considered to be inguinitis, which can be improved by medication and surgery. Swollen thumbnail with pus inside is usually caused by excessive nail clipping, ingrown nails, embedded nails and other causes of bacterial infection, the formation of inflammation will be manifested as localized swelling and pain, and in serious cases, abscesses will be formed, and need active treatment. If you have a nail infection, you can apply fusidic acid cream or mupirocin ointment locally to improve the symptoms, and you can also take antibiotics such as doxycycline and azithromycin orally to control the inflammation; In severe cases, in addition to medication, surgical treatment such as incision and drainage of pus, nail extraction, etc. is also needed to promote the recovery of the disease. The prognosis of the disease can be improved by actively cooperating with doctors to receive standardized treatment.