When you head to the doctor for an illness, it’s logical to want a prescription to feel better fast. Leaving empty handed can be frustrating — but, surprisingly, it can also be a good thing. It means your body can fight the infection. Jessica Manders, PA-C, UnityPoint Health, explains why taking an antibiotic is not always necessary and can do more harm than good if taken when it's not needed.
Bacteria vs. Virus
A bacteria is a very small organism composed of a single cell, while a virus is even smaller.
“Infections due to viruses are much more common than infections due to bacteria, especially during the fall and winter,” Manders says.
Common viral infections include colds, COVID-19, the flu and bronchitis. Viruses are the main cause of sinusitis and sore throats, although, in a very small number of cases, these infections can be caused by bacteria as well. Skin infections (cellulitis), pneumonia and urinary tract infections are common kinds of bacterial infections.
“If you have a fever over 103 F, a fever that lasts more than five days, a fast heart rate of more than 100 beats per minute or are feeling very short of breath, then you should see a healthcare provider,” Manders says.
When to Take Antibiotics
Antibiotics can save lives but must be used correctly. They only treat infections caused by a bacteria.
Manders says if you take an antibiotic when you don’t have a bacterial infection, it won't help you get any better. Also, the antibiotics will still target the good bacteria in your body. When you lose your good bacteria, certain types of bacteria, like C. diff, can grow out of control in your body and give you a very aggressive type of diarrhea.
If you’re wondering what kind of illness warrants an antibiotic, here’s a cheat sheet on when antibiotics could be an appropriate treatment.

Side Effects of Antibiotics
It’s important to be mindful that anytime you take antibiotics, they can be accompanied by a range of uncomfortable side effects, including:
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Rash
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Dizziness
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Nausea
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Vomiting
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Yeast infection
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Diarrhea
The Centers for Disease Control and Prevention (CDC) says one out of five medication-related visits to the emergency department are from reactions to antibiotics.
How Long Does it Take an Antibiotic to Work?
Antibiotics get to work as soon as they enter your system. However, how long it takes to start feeling better can vary and depends on the type and severity of the bacterial infection the antibiotic is treating. Manders says it typically takes between two and three days, while some conditions may require a two-week regimen before symptoms start to disappear. If the pep in your step returns before you’ve finished your prescription, it’s best to finish it all to wipe out any remaining bacteria that could cause a reoccurrence of the illness.
Antibiotic Resistance
Manders says another side effect of unnecessary antibiotics is some of the bacteria in your body can become resistant to antibiotics. That means if you get sick again and take the same prescription in the future, it won’t work. The CDC calls antibiotic resistance one of the biggest public health challenges of our time, reporting more than 2.8 million antimicrobial-resistance infections occur each year in the U.S. and more than 35,000 people die as a result. When C. diff develops and antibiotics aren't available due to resistance, these numbers rise to 3 million infections and 48,000 total deaths.

How to Combat Antibiotic Resistance
Manders says there are ways to help reduce antibiotic resistance, such as:
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Don't share your antibiotic with others
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Don't take antibiotics prescribed to someone else
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Don't skip doses of your prescribed antibiotic
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Don't stop an antibiotic unless instructed to by your doctor
Can You Drink While Taking Antibiotics?
If you’re taking antibiotics, always check your prescription label or ask your pharmacist on how to take the medication. In general, antibiotic effectiveness is not impacted by alcohol but can sometimes lead to unwanted side effects, such as an upset stomach. Alcohol also does have a negative impact on your immune system, which may slow down your recovery time. So, it’s a good idea to skip the alcohol until you’re feeling better again.
How to Treat a Virus
If you have a virus, and antibiotics won’t help, what can you do to treat it? Manders says it depends.
“Infections due to influenza can be treated with antivirals, but that’s not always necessary. Anti-viral medications are usually only necessary for those at high-risk for complications. Most healthy individuals can handle the flu without any medication. Viral infection symptoms are usually the worst the first three to five days of the illness and can be treated with rest, fluids and over-the-counter medications as needed for cough and congestion relief,” she says.
Talk to your doctor about which over-the-counter medication is right for you. Simply using ibuprofen or acetaminophen (Tylenol) might do the trick.