Diagnosing and Treating Cold, Flu, and Sinus Illnesses
Dec 30, 2025
This article explains a general approach to managing respiratory illnesses such as colds, flu, and similar infections. The goal is to help you understand when it makes sense to seek medical care and when symptoms can often be managed safely at home.
As a rule, most of these illnesses should initially be treated with supportive care: getting plenty of rest (both during the day and at night), staying well-hydrated with water, and using over-the-counter medications as needed to manage symptoms such as pain, fever, or congestion. These steps can often be started at home without seeing a clinician. Further testing or treatment decisions depend on which symptoms are most prominent and how the illness progresses.
When a patient comes to see me in clinic, the first thing I do is take a history (see what the symptoms are and the characteristics of each symptom). If the symptoms include fever, cough, chills, and/or body aches, I’m likely to consider influenza (“the flu”), COVID, or RSV (respiratory syncytial virus) as top possibilities. We usually perform rapid flu and COVID testing in our clinic and if positive, treat accordingly. Medication can be prescribed for influenza if within the first 48 hours of symptom onset (Tamiflu) and within 5 days of COVID symptom onset (Paxlovid). I usually only prescribe Paxlovid if a patient is at higher risk of severe illness. This includes when patients may have chronic conditions such as diabetes, immunosuppression, chronic kidney disease, COPD/emphysema, heart disease, etc.
If a patient’s main symptoms are sore throat, pain with swallowing, headache, fatigue, and NO COUGH, the most likely diagnosis is strep throat. This is tested with a rapid swab of the throat and treated with antibiotics if positive. Because viral infections can also cause sore throat, testing is important before prescribing antibiotics.
If cough is a predominant symptom, then the main thing I want to know is if this is an upper respiratory problem or a lower respiratory tract problem such as pneumonia. If I suspect a pneumonia, I might either perform a lung ultrasound or order a chest X-ray. Pneumonia (lung infection) can be a viral or bacterial illness. Imaging can sometimes suggest whether pneumonia is more likely viral or bacterial, but it is not always definitive. Bacterial pneumonia is treated with antibiotics. If severe enough, pneumonia may require hospitalization for a few days in order to recover safely. I often prescribe cough medication, which can be over the counter such as dextromethorphan (DM) containing products. Or this could be prescription cough medication such as tessalon perles (benzonatate) or stronger cough medication such as those containing codeine. Codeine-containing cough medications are used selectively due to side effects such as sedation and constipation.
If the predominant symptoms are of a sinus infection (sinusitis), then I need to see if the patient is more likely to have a viral or bacterial infection. Viruses aren’t killed by antibiotics, so it’s important to get this right. Antibiotics can occasionally come with significant side effects, including allergic reactions, diarrhea, and sometimes hospitalization related to an abdominal infection known as C diff (Clostridium Difficile).
So, if a patient has sinus pain, sinus pressure/fullness, and/or drainage coming out of the nose, this likely indicates a sinus infection. Approximately 90–95% of acute sinus infections are viral. Expert guidelines therefore recommend only prescribing antibiotics to people in the outpatient (doctor’s office) setting if the sinus infections are not improving or getting worse after 10 days of symptoms, OR the illness gets much better and then much worse again within the first 10 days (this condition is called “double worsening”). Only then are we supposed to prescribe antibiotics.
Antibiotics work by either destroying the cell wall of bacteria, preventing bacterial reproduction (replication), or killing bacteria by other means. Viruses are many times smaller than bacteria and antibiotics will simply not have any means to stop them. We don’t want to cause harm with unnecessary antibiotics, nor do we want to increase resistance to the antibiotics for our community. The more we use antibiotics, the less they work on the bacteria in our community over time. There are many antibiotics we no longer use today because antibiotic resistance has developed. If we run out of antibiotics to use, we’ll have no way to treat these infections.
In addition to the above, sinus infections are treated symptomatically. Sinus rinses, such as with a netty pot should be performed daily. Only distilled, sterile, or previously boiled (and cooled) water should be used for sinus rinses. Decongestants, such as Sudafed or Afrin nasal spray can be used for no more than 3–5 consecutive days to avoid rebound congestion. Flonase or another nasal anti-inflammatory steroid can be used to help relieve nasal inflammation.
The common cold is a type of viral upper respiratory infection. The symptoms can include sinus infection symptoms, cough, runny nose, nasal congestion, sore throat, and fatigue. Usually if there are not more serious symptoms, doctors cannot provide much help. This is one condition you may be able to wait out at home without a doctor’s appointment.
The following table summarizes what I talked about above:
| Diagnosis | Common Symptoms | Typical treatment |
|---|---|---|
| Influenza (“the flu”) virus |
|
|
| COVID virus |
|
|
| Strep throat | Sore throat, pain with swallowing, headache, fatigue | Antibiotics such as penicillin or amoxicillin (or alternative if allergic) |
| Sinus infection (sinusitis) | Sinus pain, sinus pressure, and/or sinus drainage |
|
| Common cold (viral upper respiratory infection) | Nasal congestion, runny nose, sore throat, headache, fatigue, cough |
|
Seek emergency care if you experience:
- Significant shortness of breath
- Chest pain
- Confusion
- Severe weakness of dehydration
- Oxygen levels less than 90% (if measured)
If you need an appointment for non-emergency care, we are accepting new patients and also offer same-day appointments. You can either schedule with us online at www.brightmedclinic.com or you can call us at 913-667-0800.