Some side effects of hormone replacement therapy include headaches, acne, nervousness, diarrhea and nausea. Hormone therapy often refers to estrogen or a combination of estrogen and progesterone treatment, according to MedicineNet.
Hormone replacement therapy is often used to treat women who are going through menopause. This is because their bodies no longer produce certain hormones and this can lead to a number of symptoms. Some of the issues treated by this medication include hot flashes, vaginal dryness and disturbed sleep. However, hormone replacement therapy does not relieve menopause symptoms such as depression and nervousness, notes the National Institutes of Health's MedlinePlus.
Individuals who are under hormone replacement therapy may end up experiencing side effects that include a change in sex drive and difficulty wearing contact lenses. Some women develop white or black patches on their skin. Individuals may experience stomach upset and changes in the menstrual flow. Other side effects of hormone therapy may include breast tenderness, bleeding or spotting between periods, swelling of certain body parts, stomach cramps and changes in appetite and weight.
In rare cases, individuals may develop side effects such as extreme abdominal pain, yellowing of the skin or eyes, loss of appetite, double vision, fatigue, high body temperature, dark-colored urine and light-colored stool.