How do you know if a stuffy nose needs serious medical attention, such as taking antibiotics? Doctors consider a guideline when answering this question, though many specialists say that it’s still a gray area. It’s hard to differentiate a a viral infection from a bacterial infection based on the symptoms alone.

So doctors use their professional and educated instinct—a combination of science and experience—when deciding whether a stuffy-nose case calls for an antibiotic. Here are the signs they often look for to conclude that a more potent medication is required.

1. Length of Time You’ve Been Sick

Health problems that have been hanging around for a while can evolve into a more serious health condition, such as sinus infection. Therefore, if a stuffy nose has been lingering for weeks, your likelihood of needing an antibiotic is higher.

2. Fever

If a stuffy nose is accompanied with fever and chills, you could be experiencing a bacterial infection. However, fever, shakes and chills are also common with viral infection. In determining whether you need an antibiotic, your doctor will consider your likelihood of catching fever—is it currently circulating in your community? Is the weather a factor for the health condition?—against the possibility of it as a bacterial infection. If you have flu and the weather is just bad, your doctor will probably not recommend taking antibiotics, but take ample rest instead.

3. Sore Throat

While the state of your throat already looks terrible to you, your doctor will have to look for white spots to be able to conclude that it’s a bacterial infection, before advising you to take antibiotics. Common colds start with sore throat, but without other cold symptoms like runny nose, it can be a strep throat, which is a bacterial infection and requires antibiotics to stop the dangerous bacteria. Your doctor may have to run a rapid antigen test to ensure that your case is indeed caused by bacteria.

4. Lab Test Results

This is the only one sure way to identify if you’re really in need of an antibiotic. Your doctor wil have to collect a body gunk sample (whatever you can blow out or cough up your nose) or take a throat swab. However, a lab test may not be needed if the doctor sees obvious signs of bacterial infection in the first symptoms mentioned above.

For most cases, stuffy nose is a less serious health problem that can be cured with home remedies or self-medication. However, if left unattended, it can evolve into a more serious case, which may need a more potent cure. To know whether it’s time to get yourself antibiotics, see your physician and take these health signs into consideration.