Depo Provera injections may cause a variety of side effects. Seek emergency medical help if you experience signs of an allergic reaction such as hives, itchy skin rash, difficulty breathing, or swelling of the face, tongue, or throat. Discontinue treatment and tell your doctor as soon as possible if you experience any of the following severe side effects: sudden numbness or pain, especially if it is concentrated on one side of the body; severe chest pain; sudden shortness of breath; coughing up blood; severe headache, dizziness, or fainting; vision difficulties such as double vision; bulging eyes; seizure or difficulty speaking; yellowing of the skin or whites of the eyes (jaundice); swelling of the hands, feet, or ankles; signs of an infection such as fever or chills; extreme fatigue; severely heavy menstrual periods; pain below the waist (pelvic pain), or difficult, painful, or frequent urination. Depo Provera may also cause side effects that do not require medical attention unless they worsen or last a long time. Call your doctor if the following mild side effects become bothersome: weight gain; changes in menstrual period; breast tenderness, swelling, or discharge; hot flashes; abdominal pain, cramps, or bloating; nervousness, irritability, or depression; back or joint pain; leg cramps; acne; changes in sexual desire; slight hair loss; white vaginal discharge; swelling, redness, or irritation of the vagina; difficulty sleeping, or pain, swelling, or redness at the injection site. Tell your doctor if you experience any unusual side effects or any that are not on this list during Depo Provera treatment.