Sinusitis: symptoms, causes and when it is not a cold

In short

• Sinusitis is inflammation of the sinuses, the hollow air spaces in the bones around your nose. It often starts as a cold.
• Viruses cause most sinus infections, and the CDC says most get better on their own without antibiotics.
• Signs that justify a visit are symptoms lasting more than 10 days without improvement, severe symptoms, and symptoms that get worse after improving.
• Use only distilled, sterile, or boiled and cooled water to rinse your nose, never water straight from the tap.
• Nasal decongestant sprays or drops should not be used for more than five days.

What happens in the sinuses

MedlinePlus explains that swelling inside the nose can block the sinuses, which leads to pain and pressure. Acute sinusitis often begins as a cold that becomes a bacterial infection, though allergies, nasal problems and certain diseases can also cause it.

The CDC lists the usual symptoms: a runny or stuffy nose, facial pain or pressure, headache, post-nasal drip, sore throat, cough and bad breath. The NHS adds green or yellow mucus, a reduced sense of smell, a high temperature, toothache and ear pressure.

When to suspect more than a cold

The CDC says viruses cause most sinus infections and bacteria cause some. The CDC advises seeing a provider in the following situations:

• Symptoms last more than 10 days without getting better.
• Symptoms are severe, such as a severe headache or facial pain.
• Symptoms get worse after you had started to improve.
• Fever lasts longer than three to four days.
• You have had several sinus infections in the past year.

Duration is the practical test. The NHS says sinusitis usually clears up on its own within four weeks, and MedlinePlus defines acute sinusitis as lasting up to four weeks.

Rinsing your nose safely

A saline nasal spray or rinse can ease congestion, and MedlinePlus lists nasal washes and saline sinus rinses among the supportive options. Water safety matters because tap water can carry germs that are safe to drink but dangerous in the nose.

1. Choose safe water.The CDC says to always use store-bought water labeled distilled or sterile, or tap water that has been boiled and cooled.
2. Boil correctly.Bring tap water to a rolling boil for one minute (three minutes above 6,500 feet), let it cool, and store it in a clean container with a tight cover.
3. Use a bleach step only as a last resort.If neither option is available, the CDC describes disinfecting tap water with unscented household bleach, and says this protocol is for nasal rinsing only, not drinking.
4. Follow your device's instructions.Rinse and dry the bottle or pot after each use, as the manufacturer directs.
5. Know when to stop.The CDC says to seek care immediately if you get a headache, fever, confusion or vomiting after rinsing.

What helps, and what to avoid

• Rest and fluids, and painkillers as directed on the label, which the NHS recommends for pain and fever.
• A warm compress on the nose and forehead, or steam from a bowl of hot water or a shower, as the CDC suggests.
• Avoid allergy triggers and do not smoke, according to the NHS.
• Decongestant sprays or drops: the NHS says not to use them for more than five days because they can make a blocked nose worse. It says pregnant people should not use decongestants at all, and that people with high blood pressure, heart disease, diabetes, glaucoma, thyroid problems or an enlarged prostate should ask a pharmacist or provider first.
• Steroid nasal sprays or drops, or antihistamines if allergies are involved, are options the NHS says a provider may prescribe.

When it becomes chronic

MedlinePlus sets the timeline: acute sinusitis lasts up to four weeks, subacute lasts four to 12 weeks, chronic lasts more than 12 weeks, and recurrent means several attacks within a year. The NHS says a provider may refer you to an ear, nose and throat specialist if sinusitis persists after three months of treatment, keeps coming back or affects only one side of the face.

Antibiotics: when they are really needed

The CDC says most sinus infections get better on their own without antibiotics. If you need one, providers sometimes use watchful waiting, which means waiting two to three days to see whether symptoms improve, or delayed prescribing, where you receive a prescription but wait two to three days before filling it.

The NHS adds that antibiotics are rarely needed because sinusitis is usually caused by a virus. If your provider prescribes one, take it exactly as directed and tell them about any side effects.

When to see a doctor

See your provider if you meet any of the CDC criteria above. The NHS also advises getting help if you are very unwell, if painkillers do not help or symptoms worsen, or if your immune system is weakened, for example by chemotherapy. Children aged 11 or younger should be seen by a provider, according to the NHS.

Red flags: confusion, a stiff neck, swelling around the eye or a change in vision need emergency care. Call 911.

Questions to bring:

• Is this viral or bacterial, and is watchful waiting reasonable?
• Which nasal sprays are safe with my other conditions?
• Do I need an ear, nose and throat referral, or imaging?

Questions and answers

Sources

1. CDC — Sinus infection
2. NHS — Sinusitis (sinus infection)
3. MedlinePlus — Sinusitis
4. CDC — How to safely rinse sinuses
5. NHS — Decongestants

Sources checked on 29 October 2026.