Lumps with pain in the waist after progesterone injection in mid-pregnancy are usually caused by drug injection, which can be improved by hot compresses, massages, magnesium sulfate topical compresses, and replacement of the injection site, etc. The injection site is prone to hardness and lumps due to poor absorption. The injection site of progesterone is prone to hard nodules and lumps due to malabsorption, so attention should be paid to the replacement of the injection site. If lumps are found and accompanied by pain, magnesium sulfate can be used to apply external compresses, hot towels, assisted massage to promote the absorption of lumps. Progesterone injection should be used with caution in patients with renal disease, cardiac edema, hypertension, and is contraindicated in patients with severe liver injury (worsening symptoms). Occasional side effects such as nausea, dizziness and headache can be relieved after stopping the drug. The medication should be used under the guidance of a doctor and should not be used blindly. If the lumps with pain symptoms continue to be unrelieved, it is necessary to consult a doctor in time to improve the relevant examination and standardize the treatment.