Whether a left adnexal cyst heals spontaneously or not needs to be distinguished according to its cause. In some patients, left adnexal cysts can heal spontaneously after menstruation. If the left adnexal cyst is a physiological cyst, such as a corpus luteum cyst, it usually does not require special treatment and usually forms after a woman ovulates and mostly disappears on its own after menstruation. However, when the corpus luteum cyst is too large, it needs to be taken seriously and there is a risk of rupture under external forces. If such patients experience persistently worsening abdominal pain, they should promptly go to the gynecology department of the hospital for treatment. Left adnexal cysts may also be pathological cysts, such as ovarian cystadenoma, cystic teratoma, endometriosis, etc., which usually do not heal on their own and require treatment to get better. To sum up, patients with left adnexal cyst should be further examined in hospital to decide the treatment plan after clear diagnosis by ultrasonography and abdominal MRI, and if necessary, the cyst can be removed by laparoscopy.