Most sinus infections are caused by viruses and clear up on their own within 7 to 10 days without antibiotics. Treatment focuses on managing symptoms while your body fights the infection. Only when symptoms persist beyond 10 days, worsen after initial improvement, or are severe from the start does antibiotic treatment typically come into play.
Why Most Sinus Infections Don’t Need Antibiotics
The vast majority of sinus infections start as viral illnesses, and antibiotics have no effect on viruses. Even when bacteria are involved, the infection often resolves without medication. This is why your doctor may recommend “watchful waiting” for 2 to 3 days before prescribing anything, giving your immune system a chance to handle things on its own. Some providers take a middle approach called delayed prescribing: they write the antibiotic prescription but ask you to wait a few days before filling it, so you only use it if you’re not improving.
The clinical guidelines from the American Academy of Otolaryngology define bacterial sinusitis by two patterns. The first is symptoms that persist for at least 10 days without any improvement. The second is “double worsening,” where you start to feel better and then get noticeably worse again within 10 days. If either pattern applies, antibiotics are reasonable.
What to Do at Home First
Saline nasal irrigation is one of the most effective things you can do for a sinus infection. Using a neti pot or squeeze bottle, you flush saline solution through your nasal passages to clear out mucus, allergens, and irritants. To make your own solution, mix one to two cups of distilled or previously boiled water with a quarter to half teaspoon of non-iodized salt. If you boil tap water, let it boil for a full five minutes before cooling and using it. Never use unboiled tap water, which can contain organisms that are harmless in your stomach but dangerous in your sinuses.
Warm compresses over your forehead and cheeks can ease facial pressure. Breathing in steam from a hot shower or a bowl of hot water helps loosen thick mucus. Staying well hydrated thins secretions and makes them easier to drain. Sleeping with your head slightly elevated can also reduce congestion overnight.
Over-the-Counter Medications That Help
Not all OTC sinus products work equally well. Nasal decongestant sprays (the kind you squirt directly into your nose) are effective at reducing swelling in your nasal passages, but you should limit use to three consecutive days to avoid rebound congestion, where your nose becomes more stuffed up than before once you stop.
Oral decongestants containing phenylephrine, found in many popular cold and sinus products on store shelves, are a different story. An FDA advisory panel reviewed the evidence and concluded that oral phenylephrine is clinically ineffective at reducing congestion. If you want an oral decongestant, pseudoephedrine (kept behind the pharmacy counter) is the more reliable option, though it can raise blood pressure and cause jitteriness.
Pain relievers like ibuprofen or acetaminophen can help with the facial pain and headache that come with sinus pressure. Intranasal corticosteroid sprays, available over the counter, reduce inflammation in the nasal lining and can speed up recovery, especially if allergies are contributing to the problem.
When Antibiotics Are Prescribed
When your doctor determines you have a bacterial sinus infection, the first-line antibiotic is amoxicillin, sometimes combined with clavulanate for broader coverage. A typical course runs 5 to 10 days. Finishing the full course matters: stopping early when you feel better can cause symptoms to return.
You should notice improvement within a few days of starting antibiotics. If you don’t, your doctor may switch to a different antibiotic or consider whether something else is going on, such as a structural issue or an allergy driving chronic inflammation.
Imaging and Testing
For a straightforward sinus infection, you don’t need a CT scan or any imaging at all. Clinical guidelines specifically recommend against it for uncomplicated cases, partly because imaging can’t reliably distinguish a viral infection from a bacterial one. Your doctor diagnoses acute sinusitis based on your symptoms and a physical exam.
Imaging becomes important in two scenarios. If your doctor suspects a complication, such as the infection spreading toward your eyes or brain, a CT scan or MRI is appropriate and sometimes urgent. And if you have recurring or chronic sinusitis (symptoms lasting more than 12 weeks), a CT scan helps identify structural problems like narrow drainage pathways or nasal polyps that might need surgical correction.
Chronic Sinusitis Requires a Different Approach
When sinus inflammation lasts longer than 12 weeks, the condition is classified as chronic rhinosinusitis, and simple antibiotics rarely solve it. Treatment typically starts with daily intranasal corticosteroid sprays and regular saline irrigation as long-term maintenance. If nasal polyps are present, oral steroids may be used in short bursts to shrink them.
For patients who don’t respond to these measures, endoscopic sinus surgery can widen the natural drainage openings of the sinuses, allowing mucus to flow out and medication to reach the inflamed tissue. Even with surgery, 30% to 50% of chronic sinusitis patients experience recurrent or treatment-resistant disease. For those cases, biologic therapies that target specific immune pathways involved in sinus inflammation have become available in recent years, offering a more precise approach for people who’ve exhausted conventional options.
Signs of a Serious Complication
Sinus infections very rarely become dangerous, but the sinuses sit close to the eyes and brain, so infection can occasionally spread. Seek immediate medical care if you develop swelling or redness around your eyes, double vision or other visual changes, a severe headache, swelling of your forehead, confusion, a stiff neck, or a high fever. These symptoms suggest the infection may have moved beyond the sinuses and requires urgent evaluation, often including imaging and possibly hospital treatment.