There are several common reasons for finger joint pain during the month: 1. If you suffer from rheumatoid arthritis, coupled with changes in hormone levels in your body after delivery, it can lead to changes in your immune function, which can easily cause rheumatoid arthritis to recur. Therefore, it is important to keep warm and avoid getting cold after delivery.2. Because of the poor immune function of the body during the menstrual period, it is easy for the local tissues to become infected and the infection will easily lead to pain around the joints. If the joint pain is severe, anti-inflammatory drugs should be used under the guidance of a doctor.3. If your fingers encounter cold water or are attacked by cool air during the menstrual period, it can easily lead to joint pain, so be sure to keep warm and avoid getting cold.