What is sinus infection?
Sinusitis is inflammation of the lining of the sinuses — the air-filled cavities behind your forehead, cheeks, and around your eyes. When that lining swells, mucus can't drain properly, leading to pressure, pain, and sometimes infection.
There are two main flavors. Acute sinusitis lasts less than 4 weeks and is most often viral, following a cold. Bacterial sinusitis is less common (only 0.5–2% of viral cases turn bacterial) and is usually suspected when symptoms last more than 10 days without improvement, get better then worse ("double-worsening"), or come with high fever and severe facial pain.
Chronic sinusitis lasts more than 12 weeks and may have non-infectious causes like polyps, structural issues, or allergies — these usually need ENT evaluation rather than antibiotics.
Do I have sinus infection? Common signs
If most of these describe what you're experiencing, telehealth is a reasonable next step:
What causes it
Most acute sinusitis is caused by viruses — the same ones that cause the common cold (rhinovirus, influenza, parainfluenza). Bacterial sinusitis, when it occurs, is usually caused by Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis. Risk factors include recent cold or upper respiratory infection, allergies, deviated septum or nasal polyps, dental infections, smoking, and immune system problems.
Is it contagious?
The viruses that cause most sinus infections are contagious — but the sinusitis itself isn't directly transmitted. Catching the virus from someone may or may not lead to sinusitis in you. Bacterial sinusitis is generally not contagious. Standard cold-prevention hygiene (hand washing, covering coughs) reduces transmission.
Most sinus infections clear without antibiotics — but the ones that need them really need them, and a clinician can tell the difference.
Can it be treated online?
Sinus infections fit telehealth well when symptoms are classic. A clinician can take your history, review symptom duration, look for "double-worsening" or red flags, and decide between watchful waiting, symptomatic care, or antibiotics. Bacterial sinusitis is over-diagnosed in clinic, so a careful telehealth review may actually reduce unnecessary antibiotic use.
How sinus infection is treated
For viral sinusitis: supportive care — saline nasal spray, decongestants (short-term), pain relievers, warm compresses, and time.
For bacterial sinusitis: amoxicillin-clavulanate (Augmentin) is first-line for adults; doxycycline is an alternative for penicillin-allergic patients. Treatment runs 5–10 days. Nasal steroid sprays (like fluticasone) reduce inflammation and speed recovery either way.
For allergy-driven sinus issues: nasal steroid spray, antihistamines, and allergy management.
Self-care while you wait
- Saline nasal rinse with a neti pot or squeeze bottle — use distilled, sterile, or previously boiled water only
- Steam from a hot shower or bowl of hot water
- OTC decongestants like pseudoephedrine — limit to 3 days for nasal sprays to avoid rebound congestion
- Stay well hydrated to keep mucus thin
- Sleep with head slightly elevated
- Avoid known allergens and irritants while symptomatic
How long does it last?
Viral sinusitis usually resolves within 7–10 days, sometimes lingering up to 4 weeks. Bacterial sinusitis on antibiotics typically improves within 3–5 days and clears within 10 days. Chronic sinusitis (over 12 weeks) needs in-person workup.
Frequently asked questions
How do I know if I need antibiotics?
Antibiotics are usually only helpful when symptoms last more than 10 days without improvement, when symptoms get better then suddenly worsen ("double-worsening"), or when severe symptoms (high fever plus severe facial pain) last 3+ days. Less than 2% of sinus infections that start as a cold turn bacterial.
Why is green or yellow mucus not always bacterial?
Mucus color is a poor indicator. Both viral and bacterial infections produce thick colored mucus once inflammation kicks in. Color alone doesn't justify antibiotics.
Is a neti pot safe?
Yes when used correctly with distilled, sterile, or previously boiled water (never tap water — there have been rare cases of brain infection from amoeba in tap water).
Should I keep using decongestant spray?
No more than 3 days. Oxymetazoline and similar sprays cause rebound congestion if used longer, where you become dependent on them to breathe.
Can sinusitis cause a toothache?
Yes — pressure in the maxillary sinuses can cause referred pain in upper molars. If your tooth pain comes with other sinus symptoms, sinusitis is more likely than a dental issue.


