The pain inside the nail of the thumb may be caused by nail fungus, nail fungus, nail hemangioma, trauma, etc. If the symptoms persist for a long time without significant improvement, it is recommended to seek medical advice to determine the cause, and then follow medical advice to carry out corresponding treatment, common treatment methods include medication, surgery, etc. 1, nail fungus: usually caused by microbial infection, if the thumb appears nail fungus, the tissue around the nail may The swollen tissues squeeze the nail cover, which can cause pain inside the thumb nail, and may cause purulent changes as the condition develops. It is recommended to apply topical compound polymyxin B ointment, mupirocin ointment, etc. for treatment as prescribed by the doctor. If there is a lot of pus in the affected area, it is necessary to consider incision and drainage to drain the pus. 2. Nail fungus: It may be caused by Candida infection or mycobacterial infection, and symptoms such as cloudy and separated nail plate and atrophy may occur when the nail plate of the thumb is separated, which may cause pain inside the nail of the thumb. It is necessary to take itraconazole capsules, ketoconazole capsules and other drugs as prescribed by the doctor for treatment; 3. sub nail hemangioblastoma: If hemangioblastoma appears under the nail of the thumb, the patient will feel painful and have pain inside the nail of the thumb. It needs to be treated by surgical removal under the guidance of a doctor; 4. Trauma: If the thumb is smashed or stabbed, it may lead to redness, swelling and pain under the nail tissue and pain inside the thumb nail. In this case, you can take ibuprofen extended-release capsules or celecoxib capsules and other drugs for pain relief treatment as prescribed by your doctor.