We've all been there. We're sick, busy and just want our illness to disappear. So we go to our doctor and beg for a prescription. If it's an antibiotic, it might work magic, or it might wreak havoc. It all depends on whether we really need it or not.

What do antibiotics do?

Antibiotics kill bacteria. That's all. They don't kill viruses, funguses or other disease-causing organisms. They also don't always differentiate between good bacteria and bad ones.

Antibiotics either destroy bacterial cell walls or interrupt their ability to reproduce. In order to be good medicine, antibiotics must be selective at targeting bacteria and not going after vital human cells. Several different classes of antibiotics target specific types of bacteria.

The back story

Bacterial infections cause some of the world's nastiest diseases, including tuberculosis, some types of pneumonia, meningitis, blood infections, strep and staph infections. When we're exposed to disease-causing bacteria, usually our immune system fights them off before they overproduce and cause infection.

Before penicillin (the first antibiotic) was invented in the 1920s from food mold, people died of infections every day. When medical professionals realized that antibiotics could eliminate infections and lengthen life spans, prescriptions for these medicinal miracle workers flew off doctors' script pads.

Antibiotics today

Fast forward to today, when antibiotics are doled out like cough drops, and frequently for diseases they don't cure, like colds, flu and other viruses. Patients believe in the healing powers of antibiotics and ask doctors for prescriptions. Many doctors, eager to keep patients happy, prescribe them.

Until recently, many thought antibiotics couldn't do much harm. That is, until bacteria began outsmarting antibiotics and started developing immunities to the drugs that used to annihilate them. That was the wakeup call that made the medical community realize that over-prescribing antibiotics was downright dangerous.

Supergerms, monsters and aliens

Antibiotic-resistant bacteria cause diseases like MRSA (methicillin resistant staph aureus), which can devour skin and invade muscle so fast that sometimes the only way to save a patient's life is with amputation.

Elizabeth Steiner, M.D., associate professor of Family Medicine at OHSU says, "We're undergoing a complete revolution in how we think about antibiotics. Bacteria are sneaky critters that are very evolutionary. It's critical that patients understand when they need antibiotics, when they don't and how to take them properly."

According to Steiner, antibiotics aren't entirely risk-free. In fact, she says, some patients get pretty sick taking them. "One young mother was breastfeeding her 4-month-old son. She got a cold. Her doctor prescribed antibiotics and told her to quit breastfeeding so her baby wouldn't be exposed to them. By not breastfeeding, though, her baby didn't receive the natural immunities breast milk provides. He got the cold, and that same doctor prescribed the same useless antibiotics to the baby, who developed severe diarrhea. Those antibiotics made mom and baby sicker."

It's not just unnecessary antibiotics that cause problems; it's also a matter of people taking them incorrectly. Steiner says, "When patients take them just until they feel better, or forget doses, the weakest bacteria die first, but stronger ones hang around and become resistant. Then, the next time the patient needs that antibiotic, it won't work."

That's one of the reasons the Oregon Department of Health developed the Alliance Working for Antibiotic Resistance Education (AWARE) with the Centers for Disease Control. They advise that, "Resistant bacteria can stay in your body or spread to other people ... [and] cause severe illnesses that are difficult and expensive to treat. Highly resistant bacteria ("superbugs") sometimes cause infections that can't be cured. Using antibiotics wisely ... slows the spread of resistant bacteria ... and keep life-saving antibiotics effective for years to come."

Side effect or allergy?

Antibiotics sometimes cause side effects such as rashes, stomach irritation, diarrhea and yeast infections. Steiner says, "Antibiotics can kill healthy bacteria in the gut and skin. Then normal bacteria that are usually kept under control by 'good bacteria' can grow out of control. For example, clostridium difficile is a bacterium that normally lives in the intestine. If it grows out of control, like after antibiotic use, it can cause symptoms ranging from diarrhea to life-threatening inflammation of the colon."

If you develop side effects, tell your doctor, but don't quit taking your antibiotics on your own. Let your doctor make that call. You might be able to switch to an antibiotic you can tolerate better, or get an additional medication to counteract your side effects. Taking probiotics or yogurt containing active cultures (they amount to the same thing) can help replace good bacteria and relieve side effects. However, says Steiner, "Dairy products sometimes interfere with antibiotic absorption, so ask your doctor and pharmacist when to take them."

Antibiotic allergies are far less common than side effects. Symptoms might include shortness of breath, hives, swelling of lips, face, or tongue, and fainting. In the event of such side effects, contact your doctor and/or 911 immediately.

Steiner encourages patients to question their doctors about whether they really need antibiotics. And, she adds, "We also need to empower doctors to resist patients' demands for them."

According to AWARE, research shows that even when doctors limit antibiotics, adverse health outcomes from not taking them are rare. They also say patient satisfaction doesn't decrease when doctors say, "No antibiotics," and that it increases when providers encourage self-care and symptom-management education.

AWARE provides a handy chart to help patients understand which common illnesses do and do not require antibiotics.

When it comes to many everyday illnesses, there's no pill to make them magically go away. Instead, old-school remedies like rest, fluid intake and time are generally all we need to cure what ails us. Our body's immune system and healing abilities are usually magic enough.