Many breast cancer patients worry about complications of treatment, one of which is: lymphedema, or swelling of the arms after surgery or radiation. Exercise has been thought to possibly trigger or make lymphedema worse, so some heath care providers recommend that their patients avoid exercise. However, Dr. Sarah McLaughlin, a Mayo Clinic surgeon, says exercise may help prevent lymphedema and lessen its symptoms.

Approximately 1 in 8 women will be diagnosed with breast cancer in her lifetime. And, of those women, approximately 20 percent will also get lymphedema as a result of treatment.

Dr. McLaughlin says, "Lymphedema is one of the most feared complications we have with breast cancer."

Lymphedema causes uncomfortable and unsightly swelling of the arm. Plus,

"It's a constant reminder of the treatment they went through."

Why lymphedema happens is unclear, but it likely has to do with an imbalance in the lymph system after surgery or radiation. Exercise has long been considered a no-no for women who've gone through treatment, because the thought was moving increased your risk of developing lymphedema or making it worse. But recent research shows otherwise.

"There's really, at this point, not a downside to exercise."

Dr. McLaughlin says exercise benefits just about everything.

"We tell all of our patients to exercise. Use your arm. Use your arm, and be active."

Dr. McLaughlin is researching lymphedema to find out which women are at risk in hopes of developing better ways to prevent and treat the condition.