Swelling and pain in the thumb joint of pediatric patients, excluding the cause of trauma, is most often seen in congenital stenosing tenosynovitis. The tendon of every human curved thumb has a tendon sheath, but when the maternal hormone level is not balanced, tendon sheath hyperplasia, tendon jamming, unfavorable movement, palmar swelling, and even accompanied by pressure and pain will occur. For children who have reached 1 year of age, they need to be observed for 3 months to half a year. 20% of the children can be cured on their own, while those who can’t are required to undergo surgical treatment, and are usually discharged from the hospital the next day after the operation.