What is FESS (functional endoscopic sinus surgery)?

Short answer: FESS (functional endoscopic sinus surgery) is minimally invasive surgery done through the nostrils with a thin camera called an endoscope. It widens blocked sinus openings so mucus can drain again. It is usually advised for chronic or recurrent sinusitis when a proper course of medicines hasn't helped and a CT scan shows the blockage.

Key takeaways

• FESS is done from inside the nose. There is no cut on the face.
• It opens the natural drainage pathways of the sinuses rather than removing healthy tissue.
• It is considered only after proper medical treatment and a CT scan of the sinuses.
• Most people go home the same day or the next day.
• Regular nasal douching after surgery is essential for good healing.

Dr. Prashanth's perspective

FESS is advised when blocked sinus openings keep causing sinusitis to come back. It opens the drainage pathways, eases the pressure on the face and can reduce how often infections return. What it doesn't do on its own is stop post-nasal drip. For that, regular nasal douching afterwards is essential to keep mucus from building up.

— Dr. Prashanth R. Reddy, ENT Surgeon, ENTHealth360

Top 3 signs FESS may be discussed

1. Sinusitis keeps coming back. Several infections a year, or symptoms that never fully clear for 12 weeks or more.
2. Medicines only help for a while. Sprays, rinses and courses of tablets ease things, then the blockage and pressure return.
3. Your CT scan shows blocked openings. Narrow drainage pathways, thickened lining or polyps that medicines can't clear.

Not sure where you stand? Tick through the symptom checklists first.

What happens on the day

• You come in fasting. The surgery is usually done under general anaesthesia.
• The surgeon passes the endoscope through the nostril and works on screen.
• Blocked openings are widened, and polyps or thick diseased tissue are cleared.
• No cut on the face. If the septum is bent and blocking access, it may be straightened in the same sitting.
• Many people rest for a few hours and go home the same day. Some stay one night.

Recovery at a glance

• Days 1 to 3: blocked nose, mild discomfort and some blood-tinged discharge. This is expected.
• About a week: most people are back to desk work.
• Weeks 1 to 6: follow-up cleaning visits remove crusts so the openings heal wide.
• Every day: saline nasal douching, as your surgeon advises.

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The full guide

What does "functional" mean in FESS?

The sinuses are air spaces in the bones of the face. Each one drains into the nose through a small opening. In chronic sinusitis these openings swell shut, mucus gets trapped and infections keep returning. "Functional" means the surgery aims to restore the natural drainage and airflow, keeping healthy lining in place. The key area is the ostiomeatal complex, the shared drainage zone for the maxillary, frontal and front ethmoid sinuses.

Who is FESS for?

• Chronic rhinosinusitis, with or without nasal polyps, that persists despite appropriate medical treatment.
• Recurrent acute sinusitis, with repeated infections that clear between episodes.
• Sinus problems with complications, such as spread towards the eye, which need urgent assessment.
• Selected cases of fungal sinusitis, mucoceles or blocked drainage linked to facial pain or headache.

FESS is not the first step for a simple cold or a single sinus infection. Most sinus problems settle with medicines, saline rinses and treatment of allergy.

Why a CT scan matters

A CT scan of the sinuses shows which openings are blocked, how much of each sinus is affected and how the anatomy runs close to the eye and the base of the skull. It confirms whether surgery is likely to help, and it works as the surgeon's map on the day. A nasal endoscopy in the clinic adds a direct look at the lining, polyps and any contact points inside the nose.

Can FESS help sinus headaches?

When facial pressure comes from blocked, infected sinuses, opening the drainage often eases it. Not every headache around the face is sinusitis, though. Migraine and nasal contact-point headache can feel very similar. Read Sinus headache or migraine: how can I tell? and the nasal headache and endoscopic nerve decompression guide.

Risks in plain words

• Bleeding: some ooze is normal for a few days. Heavy bleeding needs prompt review.
• Crusting and adhesions: scar bands can form while healing. Cleaning visits and douching help prevent them.
• Infection: uncommon, and usually treated with medicines.
• Change in smell: often improves as swelling settles. Rarely, it can worsen.
• Rare serious risks: injury near the eye or the base of the skull, such as a leak of the fluid around the brain. CT planning and endoscopic views are used to keep these rare.
• Return of disease: polyps and chronic sinusitis can come back, especially if follow-up care is stopped early.

Get medical advice promptly for heavy bleeding, high fever, swelling around the eye, change in vision, a severe or worsening headache, or clear watery fluid dripping from the nose.

Nasal douching after surgery

Saline douching washes out mucus, old blood and crusts so the new openings stay clear. It also keeps mucus from pooling and running down the back of the throat. Use sterile or boiled-and-cooled water with the salt sachets or bottle your surgeon recommends. Many people keep douching for several weeks, and some continue long term if allergy or polyps are part of the picture.

Does FESS cure sinusitis for good?

FESS corrects the blockage. The tendency to sinusitis, allergy or polyps can remain. Long-term control usually combines surgery with ongoing care: douching, steroid sprays where advised and treatment of allergy. See Will sinus come back after surgery?

Frequently asked questions

Is FESS done through the nose or the face? Through the nostrils, with an endoscope. There is no cut on the face.

How long does FESS take? Often one to two hours, depending on how many sinuses need opening and whether the septum is corrected at the same time.

Will I have nasal packing? Many surgeons now use dissolvable packs or none at all. Your surgeon will explain the plan for your case.

When can I go back to work? Most people return to desk work in about a week. Heavy lifting and strenuous exercise usually wait around two weeks.

Will FESS stop post-nasal drip? Not on its own. Regular nasal douching after surgery is what keeps mucus from building up.

Do I need a CT scan before FESS? Yes. A CT scan of the sinuses is needed to confirm the blockage and plan the surgery.

References

• Fokkens WJ, Lund VJ, Hopkins C, et al. European Position Paper on Rhinosinusitis and Nasal Polyps 2020. Rhinology. 2020;58(Suppl S29):1-464.
• Orlandi RR, Kingdom TT, Smith TL, et al. International consensus statement on allergy and rhinology: rhinosinusitis 2021. International Forum of Allergy & Rhinology. 2021;11(3):213-739.
• Rosenfeld RM, Piccirillo JF, Chandrasekhar SS, et al. Clinical practice guideline (update): adult sinusitis. Otolaryngology–Head and Neck Surgery. 2015;152(2 Suppl):S1-S39.
• Stammberger H. Endoscopic endonasal surgery: concepts in treatment of recurring rhinosinusitis. Part I. Otolaryngology–Head and Neck Surgery. 1986;94(2):143-147.
• Harvey R, Hannan SA, Badia L, Scadding G. Nasal saline irrigations for the symptoms of chronic rhinosinusitis. Cochrane Database of Systematic Reviews. 2007;(3):CD006394.

About the author

Dr. Prashanth R. Reddy is a Senior Consultant ENT Surgeon at ENTHealth360, Bengaluru (MS ENT; Fellowship in Rhinoplasty, Seoul; MBA, IIM Bangalore), with decades of experience in endoscopic nose and sinus surgery. He sees patients at Sakra World Hospital, Marathahalli, and at his Koramangala clinic.

Medically reviewed by Dr. Prashanth R. Reddy. Last reviewed 9 Nov 2026.

Next step: if sinusitis keeps coming back, see an ENT specialist for an evaluation. Book a consultation.

Related reading: How long is recovery after sinus surgery? · Is sinus curable permanently? · Symptom checklists

For educational purposes only. Not a substitute for medical advice. Please consult a qualified ENT specialist.