Most sinus infections get better on their own, and most don’t need antibiotics. The CDC says viruses cause most sinus infections, and antibiotics don’t work on viruses. Even when bacteria are involved, a Cochrane review of 15 trials found antibiotics help only a small number of extra people get better faster, while causing side effects in more.
This guide explains the research, how to ease symptoms at home, when to see a doctor, and how allergies can set the stage for sinus problems. For more, see our allergy treatment guides.
Jump to: Quick answer · The evidence · Symptom relief · When to see a doctor · Allergies and sinus infections · FAQ
Quick answer
- Usually viral: viruses cause most sinus infections, and most improve without antibiotics (CDC).
- Small benefit, more side effects: for every 100 adults treated, antibiotics help about 5 to 11 more get better faster, but 13 more have side effects (Cochrane).
- Many recover anyway: without antibiotics, 46% were cured after one week and 64% after two weeks.
- See a doctor for severe symptoms, symptoms lasting over 10 days, symptoms that get worse after improving, or fever lasting more than 3 to 4 days.
- Allergies are a risk factor, so treating them may help prevent repeat infections.
What the research shows
| Study | Who | Findings |
|---|---|---|
| Lemiengre et al., 2018, Cochrane review | 15 trials, 3,057 adults with acute sinusitis | Without antibiotics, 46% were cured at 1 week and 64% at 2 weeks. Antibiotics helped 5 to 11 more people per 100 get better faster, but 13 more per 100 had side effects. The authors concluded there is no place for antibiotics in uncomplicated acute sinusitis. |
| Williamson et al., 2007, JAMA (UK) | 240 adults at 58 family practices | Neither amoxicillin nor a steroid nasal spray (budesonide), alone or together, was effective. Symptoms lasting 10 days or more: 29% with amoxicillin vs 33.6% without. A secondary analysis suggested the spray helped people with milder symptoms. |
Important limits: the Cochrane review couldn’t draw conclusions for children, people with weakened immune systems or severe sinusitis, because those groups weren’t in the trials. Your doctor may still prescribe antibiotics in some situations.
How to ease sinus symptoms
The CDC suggests:
- A warm compress over your nose and forehead to ease pressure.
- A decongestant or saline nasal spray. Don’t use decongestant sprays for more than a few days at a time unless your doctor says so; see allergy medicines and sleep.
- Breathing in steam from a bowl of hot water or a shower.
Saline rinses are another option; if you use a neti pot, use only distilled, sterile or boiled and cooled water. See how to use a neti pot safely.
When to see a doctor
The CDC advises seeing a healthcare provider if you have:
- Severe symptoms
- Symptoms that get worse after first improving
- Symptoms lasting more than 10 days without getting better
- A fever lasting more than 3 to 4 days
- Multiple sinus infections in the past year
Your provider may suggest waiting 2 to 3 days to see if you improve before deciding on antibiotics.
Allergies and sinus infections
The CDC lists seasonal allergies, nasal polyps, smoking or secondhand smoke, a recent cold and a weakened immune system as risk factors. If you get sinus infections often, ask whether allergies could be involved; an allergist can test you and suggest treatment such as nasal steroid sprays or allergy shots or tablets.
Other prevention steps from the CDC: wash your hands often, stay up to date on recommended vaccines such as flu, avoid close contact with people who have colds, don’t smoke, and keep any humidifier clean. See how to use a humidifier safely.
Not sure if it’s a cold, allergies or a sinus infection? Read cold vs allergies.
This guide is general information, not medical advice. Read our medical disclaimer.
Frequently asked questions
Do I need antibiotics for a sinus infection?
Usually not. Most are caused by viruses and get better on their own. A Cochrane review found antibiotics help only a few extra people per 100 recover faster, while causing side effects in more.
How long does a sinus infection last without antibiotics?
In trials, 46% of adults were cured after one week and 64% after two weeks without antibiotics. See a doctor if symptoms last more than 10 days without improving.
When is a sinus infection serious?
See a provider for severe symptoms, symptoms that worsen after improving, fever lasting more than 3 to 4 days, or symptoms beyond 10 days.
Can allergies cause sinus infections?
The CDC lists seasonal allergies as a risk factor. Treating allergies may help if you get frequent sinus infections.
Do steroid nasal sprays help sinus infections?
In a UK trial, a steroid spray wasn’t effective overall, though it seemed to help people with milder symptoms. Ask your doctor.
Sources
- Lemiengre MB, van Driel ML, Merenstein D, et al. Antibiotics for acute rhinosinusitis in adults. Cochrane Database Syst Rev. 2018;9:CD006089.
- Williamson IG, Rumsby K, Benge S, et al. Antibiotics and topical nasal steroid for treatment of acute maxillary sinusitis: a randomized controlled trial. JAMA. 2007;298(21):2487-2496.
- Centers for Disease Control and Prevention. Sinus infection basics. April 17, 2024.
Last reviewed: October 21, 2026.
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