Nausea and vomiting. This side effect is less common with hormonal therapy than it is with chemotherapy. Nausea often goes away on its own. Women can help manage symptoms by eating bland foods such as crackers, toast, and cereal, and drinking lots of fluids – 6 to 8 glasses of liquids such as water, broth, or Gatorade. The doctor or nurse may recommend anti-nausea medications or anti-anxiety medications that prevent or treat nausea or vomiting. If dehydration occurs, intravenous fluids may be needed.

Diarrhea. Diarrhea is a less common side effect of hormone therapy. Dietary measures such as eating a bland diet and avoiding foods such as dairy products and spicy foods can help reduce symptoms. Medications such as loperamide (Imodium) and diphenoxylate (Lomotil) can be used to treat diarrhea.

Constipation. Constipation is a less common side effect of hormone therapy. Daily exercise, eating foods high in fiber such as uncooked fruits and vegetables and whole grain breads and cereals and drinking lots of liquids -- 6 to 8 glasses a day -- can help ease symptoms. If these measures do not work, medicines such as a stool softener or laxative may be needed.

Weight gain. A daily exercise routine of 20 to 30 minutes per day and a weight management program can be helpful. Eating foods low in fat, such as fruits and vegetables is a good idea.

Mood swings. Nervousness, depression, and anxiety are some of the symptoms that women may experience. It is natural to experience strong emotions in response to a diagnosis of breast cancer. These may become stronger when a woman receives hormonal therapy. Relaxation, meditation, and yoga may be useful in controlling mood swings. Exercise may help toward boosting mood and relieving anxiety. Support groups and professional counselors may be helpful for some women. Antidepressants may be prescribed.

Pain, including pain in joints, back, and bones. For mild to moderate pain, over-the-counter pain medication can help alleviate pain in various parts of the body, such as the joints or back. Pain felt at an injection site can be treated with warm or cold compresses. A topical anesthetic cream may also be used.

Cough. Certain hormonal therapies such as the aromatase inhibitor anastrozole can increase coughing symptoms. Women should try to drink at least 8 glasses of fluid a day to keep the lining of the breathing tube moist. Using a humidifier to increase the moisture in the air is also a good idea. Medicines such as dextromethorphan, benzonatate, and guaifenesin may be used to stop or control coughing.

Osteoporosis. Osteoporosis is a disorder in which bones become porous and break more easily. Women who have gone through menopause have a higher risk of bone loss. Tamoxifen may lower bone loss in postmenopausal women. Other hormone therapies may not prevent or modify a woman's risk of getting osteoporosis. For this reason, postmenopausal women with breast cancer should have a bone mineral analysis to determine if a preventive therapy should be used.

Women treated with hormonal therapy should have routine screenings (bone density scans) for osteoporosis. The following suggestions are recommended for people at risk:

  • Take calcium and vitamin Dsupplements
  • Get regular physical activity, including weight-bearing exercises that put stress on bones, such as jogging, stair climbing, dancing, and resistance exercises such as weight lifting.
  • Quit smoking
  • Modify alcohol intake

Medications that prevent bone loss include the bisphosphonates risedronate and alendronate. These two drugs, along with raloxifene and calcitonin, are available to treat osteoporosis. In postmenopausal women, tamoxifen has been shown to increase bone density. However, in women who have not been through menopause, tamoxifen seems to increase bone loss. Women should talk to their doctor about which medicines, if any, would be best for them.

Rare But Serious Side Effects

Endometrial cancer. Although most side effects of hormonal therapy are not life-threatening, in very rare (less than or equal to 1%) cases, tamoxifen can raise a woman's chances of getting endometrial cancer, which occurs in the lining of the uterus. Women taking tamoxifen should report any unusual vaginal discharge, vaginal bleeding, menstrual irregularities, or pain or pressure in the lower abdomen to their doctor or nurse. Annual pelvic examinations to look for signs of cancer are also recommended.

Blood clots. Some hormonal therapies, such as tamoxifen, carry a slight risk (about 1% over 5 years) of blood clots forming in the deep blood vessels of the legs and groin. Clots can break off and spread to the lungs. Blood clots stop the flow of blood and can cause serious medical problems. Signs of a blood clot in the lungs include sudden chest pain, shortness of breath, or coughing up blood. Symptoms of a blood clot in the legs include pain, swelling, or tenderness in the groin or legs. Women should let their doctor know if they have a history of blood clots. They should also report any of these symptoms to the doctor or nurse as soon as possible.

Effects on the eye. Tamoxifen can cause cataracts or changes to parts of the eye called the cornea or retina. Women should report any vision changes -- including an inability to tell the difference between colors--to their healthcare provider.

Stroke. Tamoxifen increases a woman's chance of having a stroke. Symptoms of stroke include weakness, difficulty walking or talking, or numbness. Women should immediately report these symptoms to their doctor.