Prescription drugs heal us when we’re sick, ease our pain when we ache, and prevent or control long-term conditions. But sometimes, even when they do the job they’re supposed to, they have unwelcome side effects.

Don’t let that make you automatically rule out a medication, especially if it’s an important part of managing a health condition. But you shouldn’t accept unpleasant reactions without question, either.

Know What to Expect

Side effects can happen with almost any medicine, says Jim Owen, doctor of pharmacy and vice president of practice and science affairs at the American Pharmacists Association. They’re common with everything from birth control pills to cancer-fighting chemotherapy drugs.

Others — like antidepressants, muscle relaxants, or blood pressure or diabetes meds — may cause dizziness. Some might make you feel drowsy, depressed, or irritable. Some may cause weight gain. Some may disrupt your sleep or your ability (or desire) for sex.

Many prescription drugs, for example, cause stomach problems like nausea, diarrhea, or constipation because they pass through your digestive system.

“I tell my patients that chronic symptoms are not acceptable,” says Lisa Liu, MD, a family doctor at Gottleib Memorial Hospital in Melrose Park, IL. “I won’t allow them to have ongoing pain or discomfort unless we have tried every alternative.”