Hello, You are suffering from sore and swollen thumb. It is stiff and hard. When you try to bend it the pain is intense. You don t remember getting hurt. It can be due to rheumatoid arthritis, it can cause inflammation of the tendons surrounding the thumb called tendonitis and causing pain in the joint. It may also be due to carpal tunnel syndrome, it occurs when the median nerve is compressed at the wrist and causes thumb joint pain and sometimes tingling and numbness. However, you are suggested to get clinically examined by an Orthopedics, to assess for carpal tunnel syndrome, get CRP, anti- CCP , ESR, tests done to detect or rule out RA. Your symptom may be indicative of dislocation. Dislocation of the CMC is very common and pain is felt when the patient attempts to move the thumb. Get X-ray of the affected area done to detect any fracture or ligament injury. You will be treated accordingly (conservative, crepe bandage or plaster). At present, do not strain the thumb. Keep it at rest. you can take pain relieving medicines like Combiflam, one SOS after food for relief from pain. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician