Vaccines are foreign stimuli to the body, and after vaccination, systemic and localized adverse reactions may occur to varying degrees. Some vaccines because it contains adsorbent, after vaccination, the adsorbent at the site of vaccination is not fully absorbed, the adsorbent can stimulate the connective tissue at the site of vaccination to proliferate, thus forming hard lumps or hard nodules. The principle of treatment of hard nodules is: when the redness, swelling and hard nodules are less than 15mm, no special treatment is needed, and observation can be done. When the diameter of redness and swelling and hardness between 15-30mm, you can first use a clean towel to apply cold compresses, and then hot compresses after the emergence of hardness, 10-15 minutes each time, 3-4 times a day. If the diameter of redness and hardness is larger than 30mm, it is better to go to the hospital.