FESS Step by Step: How Functional Endoscopic Sinus Surgery Opens Blocked Sinuses

The box of tissues has become furniture. Someone in your household has tried the saline rinses, finished the steroid sprays, swallowed two courses of antibiotics, and still wakes each morning with a face that feels packed with wet sand. Their doctor has now said the word “surgery,” and the first thing they do is what most of us do: type it into a search bar at eleven at night.

What comes back is a wall of jargon. Uncinectomy. Ethmoidectomy. Middle meatal antrostomy. Somewhere in there is the fess procedure step by step, but it is buried under diagrams that look like maps of a cave system.

This explainer is the version a good ear, nose and throat surgeon would sketch on the back of an appointment card: what is actually blocked, what the endoscope does about it, what the day itself looks like, and what the following weeks tend to bring. It stays close to the published evidence and leaves every decision where it belongs, with you and your treating team.

What is the fess procedure step by step, in one plain picture?

Start with the plumbing. Your sinuses are air-filled pockets in the bones of the face, lined with a thin membrane that produces mucus and sweeps it out through small openings into the nose. An endoscope is a slim rigid tube with a light and a camera at the tip. “Functional” endoscopic sinus surgery means the surgeon uses that camera to widen the natural openings so the sinuses can drain and ventilate on their own again, rather than removing the sinus lining wholesale or creating new holes elsewhere.

Reduced to its skeleton, the fess procedure step by step runs like this. First, imaging and a clinic endoscopy map exactly where the blockage sits. Second, on the day, you receive anesthesia and the nose is treated with medicine to shrink the lining and reduce bleeding. Third, the endoscope goes in through a nostril; nothing is cut on the outside of the face. Fourth, the surgeon removes the specific obstructions: a thin curtain of bone here, a swollen ridge there, polyps if present. Fifth, the openings of the affected sinuses are enlarged just enough to restore flow. Sixth, any bleeding is controlled and, sometimes, a dissolvable dressing is placed. Seventh, you wake, are watched for a few hours, and in most cases go home the same day, according to Cleveland Clinic’s overview of the operation.

Everything that follows in this article is a slower walk through those seven steps, with the honest caveats attached. The one idea worth holding onto from the start: the surgery does not remove your sinuses or “clean them out” like a drain. It reopens doors that swelling has jammed shut.

How does FESS actually work: the mechanics of a blocked sinus

Picture a small room with one narrow door that opens into a hallway. The room is a sinus; the hallway is your nasal cavity. The lining of the room is a living carpet of cells with microscopic hairs, called cilia, that beat in a coordinated wave and push mucus toward the door. In health, the door is a few millimeters wide, mucus slides out, air moves in, and you notice none of it.

Chronic sinusitis is what happens when that door swells partly shut for 12 weeks or more despite treatment, the threshold used by Mayo Clinic and the NHS. Mucus backs up, the room loses its ventilation, the lining thickens further in response, and bacteria or fungi find a warm, damp, poorly drained space. Each element feeds the next. Steroid sprays and rinses try to shrink the swelling from the outside; when that fails, the anatomy itself is often the limiting factor.

The critical real estate is a small region between the eye and the nose called the ostiomeatal complex, a shared corridor into which the frontal, maxillary and anterior ethmoid sinuses all drain. A modest amount of swelling or a slightly unusual bone shape here can block three sinuses at once. That is why a surgeon may remove only a few millimeters of tissue and still change how an entire side of the face drains.

Functional surgery works on a single principle: restore the natural pathway and let the lining recover on its own. Studies summarized by Johns Hopkins and Mayo Clinic describe the goal as improving drainage and, just as importantly, letting topical medicines such as steroid rinses reach lining they could not reach before. The operation is often less a replacement for medical treatment than a way of making that treatment finally work.

Who is FESS usually for, and who is usually asked to wait?

Surgery is not the first rung on the ladder, and the guidance from every major source agrees on that. Mayo Clinic and the NHS describe endoscopic sinus surgery as an option when chronic sinusitis has persisted despite an adequate trial of medical management, which typically includes saline irrigation, intranasal corticosteroid sprays and, where infection is suspected, antibiotics chosen by the treating clinician.

People commonly considered for FESS fall into a few groups:

• Adults with chronic rhinosinusitis confirmed on a CT scan and nasal endoscopy, whose symptoms have not settled after weeks to months of maximal medical therapy.
• People with nasal polyps, soft grape-like swellings of the lining, that block breathing or drainage and have not shrunk enough with steroid treatment.
• Those with recurrent acute infections whose scans show a structural narrowing the medicines cannot fix.
• Less common indications such as fungal sinus disease, mucoceles (mucus-filled cysts that expand and press on bone), or the need to reach adjacent structures for other operations.

Who is usually asked to wait, or steered elsewhere? Someone with symptoms but a clear CT scan, because the operation targets what the scan shows; a person in the middle of an acute infection, since inflamed tissue bleeds more and swelling can hide landmarks; someone whose headaches or facial pain have a likelier cause such as migraine, a distinction Mayo Clinic notes is easy to blur; and children, in whom the NHS and Cleveland Clinic describe surgery as reserved for select cases after other measures, because sinuses are still developing and adenoid enlargement is often the real culprit.

None of these are hard walls. They are the questions your ear, nose and throat specialist will be weighing, and the honest conversation to ask for is the one that explains which group you fall into and why.

What happens before the operation: scans, checks and stopping points

The most important part of the fess procedure step by step happens before anyone picks up an instrument. A CT scan, a series of X-ray slices assembled into a three-dimensional picture, shows the surgeon which sinuses are blocked, how thick the lining is, and, crucially, where your own anatomy differs from the textbook. The thin bone separating the ethmoid sinuses from the eye socket, and the roof of the ethmoids beneath the brain, vary from person to person by a few millimeters. The scan is the map that keeps those neighbors safe.

Alongside imaging, you will usually have a clinic nasal endoscopy, a quick look inside with a numbing spray, so the surgeon can match what the scan shows with what is visible. Many teams also arrange the CT in a format that can be loaded into a navigation system on the day, which tracks the instrument tip against your scan in real time, an approach Johns Hopkins describes for revision or complex cases.

The pre-operative checklist tends to cover:

• A review of every medicine and supplement you take, because some thin the blood and your surgical and prescribing teams will decide together whether and when any should be paused. Do not stop anything on your own.
• Questions about bleeding tendencies, previous anesthetics, sleep apnea and smoking, since smoking slows lining recovery.
• Fasting instructions, typically no food for several hours beforehand, set by the anesthesia team.
• Arranging a responsible adult to take you home and stay the first night.

If you are having a flare of infection near the date, tell the team. Postponing by a week or two to let the tissue calm down is common and is a sign of good planning, not a setback.

What happens during FESS: the fess procedure step by step in the operating room

Once you are asleep or comfortably numbed, the nose is prepared with pledgets, small strips of cotton soaked in medicine that constricts blood vessels and shrinks the lining. This step matters more than it sounds: a dry field lets the camera see, and seeing is the entire point of the operation.

The surgeon then introduces the endoscope through one nostril, watching a monitor rather than looking down into the nose. Instruments a few millimeters wide pass alongside it. Working outward from the front of the nose, the classic sequence is:

• Uncinectomy: removal of the uncinate process, a thin sickle of bone that acts like a hinged door in front of the sinus openings. Taking it away exposes the corridor behind it.
• Maxillary antrostomy: enlarging the natural opening of the maxillary sinus, the large cheek sinus, so mucus can drain rather than pool.
• Ethmoidectomy: opening the honeycomb of small ethmoid cells between the eyes, first the anterior group, then the posterior group if the scan shows disease there.
• Sphenoidotomy: widening the opening of the sphenoid sinus, which sits deep behind the ethmoids, when it is involved.
• Frontal recess work: clearing the narrow channel that leads up to the frontal sinus above the eyebrow, one of the most delicate areas because of its proximity to the eye and brain.

Polyps are removed with a microdebrider, a powered instrument that shaves and suctions tissue at the same time. At the end, the surgeon checks each opening, controls bleeding, and may leave a dissolvable spacer or a light dressing. Cleveland Clinic notes the operation typically takes somewhere in the range of one to a few hours depending on how many sinuses are treated and whether both sides are done. You wake in recovery with a small gauze pad under the nose to catch the expected trickle of blood-tinged fluid.

Which sinuses are opened, and what each step is called

The names on a surgical consent form can look like a foreign language. The table below translates the common ones. Not every operation includes every row; the surgeon chooses steps based on which sinuses your CT scan shows to be blocked. “Full-house” FESS, in which every sinus on both sides is opened, is reserved for widespread disease such as extensive polyps.

Sinus	Where it sits	Surgical step	What is actually done
Maxillary	Behind each cheek	Middle meatal antrostomy	Natural opening is widened so gravity and cilia can clear mucus
Anterior ethmoid	Between the eyes, toward the front	Anterior ethmoidectomy	Thin bony partitions are removed to create one open cavity
Posterior ethmoid	Between the eyes, further back	Posterior ethmoidectomy	Deeper cells are opened when the scan shows disease there
Sphenoid	Deep in the skull, behind the ethmoids	Sphenoidotomy	Front wall opening is enlarged under direct view
Frontal	Above each eyebrow	Frontal recess dissection	Narrow drainage channel is cleared of obstructing cells
Nasal cavity (not a sinus)	Center of the nose	Septoplasty or turbinate reduction	Sometimes added to improve access or airflow

A few points the table cannot show. The steps are cumulative in the sense that each one opens the view for the next; the uncinectomy is almost always first for that reason. The frontal recess and sphenoid carry the highest technical demand because the bone between them and the eye or brain is thinnest, which is why surgeons often reserve them for when disease clearly requires it. And a septoplasty, straightening the wall between the nostrils, is not part of FESS itself, but is frequently combined with it when a bent septum blocks access or airflow, a pairing both Mayo Clinic and Cleveland Clinic describe.

Will I be awake? Anesthesia, time and what the surgeon sees

Most FESS in adults and essentially all in children is done under general anesthesia, meaning you are fully asleep with a breathing tube protecting your airway, according to Cleveland Clinic and Johns Hopkins. Some surgeons perform limited procedures, such as a small polyp removal or a single-sinus opening, under local anesthesia with sedation, in which the nose is numbed and you are drowsy but breathing on your own. The choice depends on how much needs to be done, your general health, and your preference, and the anesthesia team makes the final call.

The view on the monitor is unlike what you might imagine. Because the endoscope magnifies, the surgeon sees tissue at a scale where individual blood vessels are visible and a two-millimeter bony landmark fills a good part of the screen. Angled telescopes, with lenses set at 30 or 70 degrees, let the surgeon look around corners into the maxillary and frontal sinuses without moving the tube itself. This is why the outside of the face is never cut: the camera does the traveling.

Duration varies with the number of sinuses. A one-sided procedure on two sinuses may be under an hour of operating time; extensive bilateral polyp surgery with frontal work can run to a few hours, a range consistent with Cleveland Clinic’s description. Add the time for anesthesia induction and recovery, and a morning or afternoon in the day-surgery unit is the typical footprint.

Image guidance deserves a word. A navigation system compares the tracked instrument against your pre-operative CT, showing its position on three views at once. It does not replace anatomical knowledge, and it does not make the operation risk-free, but many surgeons use it routinely for revision surgery, extensive polyps, or anatomy that the scan shows to be unusual.

What the first 48 hours after endoscopic sinus surgery usually look like

Expect to feel as though you have the worst head cold of your adult life, without much pain. That is the honest summary most people give. The nose is blocked with swelling, clot and any dressing left in place, so you breathe through your mouth and your voice sounds odd. A slow trickle of blood-streaked mucus from the nostrils is normal for the first day or two, and the gauze pad under the nose is changed as it soaks, according to Cleveland Clinic’s aftercare guidance.

Pain is usually described as pressure or a dull ache across the cheeks and between the eyes rather than sharp pain, and simple pain relief chosen by your team generally controls it. Some people have a headache from the pressure change, some notice a sore throat from the breathing tube, and fatigue from the anesthetic is universal.

The routines that matter in this window:

• Sleep with your head raised on two or three pillows, which reduces both swelling and bleeding.
• Do not blow your nose. Sniff gently if you must, and sneeze with your mouth open to spare the healing tissue.
• Avoid bending, lifting and straining, all of which raise pressure in the head.
• Start saline rinses when your surgeon says to, often within a day or two; they float away dried blood and are the single most repeated instruction in FESS aftercare.
• Skip hot showers and hot drinks on the first day if your team advises, since heat dilates vessels.

You will usually be given specific instructions on which of your regular medicines to resume and when, particularly anything affecting bleeding. Follow those exactly and ask if anything is unclear. Most people describe the second day as slightly worse than the first as swelling peaks, and the third as the turning point.

Endoscopic sinus surgery recovery: what the following weeks usually bring

Healing inside the nose is slow and largely invisible to you. The lining you cannot see is regrowing over raw bone, crusts are forming and shedding, and the widened openings are settling into their final shape. Cleveland Clinic describes most people returning to desk-based work within about one to two weeks, with strenuous exercise and heavy lifting held off for longer as advised by the surgeon, while full lining recovery inside the sinuses takes considerably longer. Treat these as typical ranges, not promises; your own timeline depends on how extensive the surgery was and how you heal.

A rough shape of the weeks:

• Week one: congestion, crusting, occasional blood-tinged discharge, low energy. Rinses several times a day. The first post-operative visit often falls in this week or the next.
• Weeks two to three: breathing starts to open as swelling subsides. Smell, which can be dulled by swelling, often begins to return. A debridement, in which the surgeon gently suctions crusts and clot from the cavities in clinic, may be done to keep the openings clear.
• Weeks four to eight: most day-to-day symptoms have eased. Rinses may continue long term, and steroid sprays or rinses are frequently restarted so they can reach lining that was inaccessible before surgery.

Two things surprise people. The first is how much the follow-up visits matter: clinic debridements are part of the treatment, not an afterthought, because scar tissue can bridge and narrow the new openings if crusts are left in place. The second is that the operation is a beginning rather than an end. Chronic sinusitis is an inflammatory condition, and the surgery changes the anatomy so that ongoing medical care, decided with your ear, nose and throat team, can control it more effectively than before.

FESS surgery risks: what the evidence actually says

Any honest explainer has to sit with the neighbors of the sinuses: the eyes on either side and the brain above. FESS is considered a safe operation in experienced hands, and serious complications are uncommon, but they are real, and the consent conversation exists to name them. Mayo Clinic and Cleveland Clinic list the following, in roughly descending order of how often they are encountered.

• Bleeding: expected in small amounts; heavier bleeding needing packing or a return to the operating room is uncommon.
• Infection: the sinuses are already colonized with bacteria, and infection after surgery is treated by the team if it occurs.
• Scarring or adhesions: bands of scar tissue that can narrow the new openings, the main reason for clinic debridements and, occasionally, revision surgery.
• Changes in smell or taste: usually temporary, related to swelling, though rarely persistent.
• Eye injury: bruising around the eye is occasionally seen; damage to the eye muscles, tear duct or vision is rare but is the reason the ethmoid bone next to the orbit is handled with such care.
• Cerebrospinal fluid leak: a breach of the thin bone beneath the brain allowing the clear fluid that cushions it to escape. Rare, usually recognized and repaired during the same operation if it happens.
• Persistent or recurrent symptoms: surgery corrects anatomy, not the underlying inflammatory tendency, so some people need continued medical treatment or further surgery.

Numbers vary between studies and depend heavily on how extensive the surgery is, so this article deliberately avoids quoting percentages that would apply to no individual patient. What the mainstream evidence supports is a general statement: major complications are rare, minor ones are relatively common and usually self-limiting, and the risk profile is discussed specifically with each patient before consent. Ask your surgeon to describe the risks as they apply to your scan.

What are the alternatives to sinus surgery, and when are they enough?

For most people with sinus symptoms, surgery never enters the conversation, and it is worth remembering why. The NHS notes that sinusitis usually clears on its own within two to three weeks, and the CDC points out that most acute sinus infections are viral, which is why antibiotics are not routinely helpful. The path to surgery runs through weeks and months of medical management first.

The mainstays, all described by Mayo Clinic and the NHS:

• Saline irrigation: rinsing the nose with salt water washes out mucus and irritants and helps cilia function. Low risk, widely recommended, and continued after surgery too.
• Intranasal corticosteroids: sprays or rinses that reduce lining inflammation directly. They take days to weeks to show full effect and are the backbone of long-term control.
• Antibiotics: reserved for suspected bacterial infection, with the choice and duration decided by the prescribing clinician.
• Short courses of oral corticosteroids: sometimes used for polyps to shrink them quickly, with the trade-offs weighed by the prescribing doctor.
• Allergy management: identifying and controlling triggers when allergic rhinitis drives the inflammation.
• Biologic medicines: injectable antibody treatments that target specific inflammatory pathways, described by Mayo Clinic as an option for some people with severe polyps. Whether they suit a given person, and how they compare with surgery in that individual, is a specialist decision.

Then there are procedural alternatives short of FESS. Balloon sinus dilation uses a small balloon passed into a sinus opening and inflated to widen it without removing tissue; it suits selected anatomy and is not appropriate for polyps or extensive ethmoid disease. Polypectomy alone removes polyps without opening the sinuses. Each has a narrower target than FESS, which is precisely why the pre-operative scan matters so much in choosing between them.

What people often get wrong about FESS

Some misconceptions come up so reliably in clinic that they deserve their own space.

“They will cut my face or break my nose.” FESS is performed entirely through the nostrils with a camera. There are no external incisions, no facial bruising in the ordinary course, and the shape of the nose does not change unless a septoplasty or other procedure is deliberately added.

“They scrape out the sinuses.” The functional philosophy is the opposite. Lining is preserved wherever possible because it is the lining, with its cilia, that keeps a sinus healthy. The surgeon removes obstructing bone and diseased tissue, then relies on your own lining to recover.

“The nose will be packed with meters of gauze.” Traditional packing has largely given way to dissolvable dressings or no packing at all, as Cleveland Clinic describes. Some surgeons still use a light removable dressing for a day or two, but the dreaded yank at the follow-up visit is far less common than older accounts suggest.

“After surgery I will never need sprays again.” Chronic sinusitis is inflammatory. Surgery reshapes the anatomy so that medical treatment can reach and control the inflammation. Many people continue rinses or steroid treatment afterward, often with far better effect than before.

“Surgery fixes sinus headaches.” Only if the headaches are actually caused by sinus blockage shown on a scan. Mayo Clinic notes that many self-diagnosed “sinus headaches” are migraines, which surgery does not help. A clear CT with headache as the main complaint is a reason to look elsewhere, not to operate.

“Once is enough.” Sometimes. But polyps in particular can regrow over years, and revision surgery is a recognized part of managing the condition rather than a sign the first operation failed.

Questions to ask your care team before FESS

A consultation goes better when you arrive with questions written down. These are the ones that tend to unlock the most useful answers, grouped by the stage they belong to.

About the diagnosis and the decision

• What exactly does my CT scan show, and which sinuses are involved?
• Have I had an adequate trial of medical treatment, and how are you defining adequate in my case?
• Could something other than sinusitis, such as migraine or allergy, be driving my main symptom?
• What would you expect to happen if I chose not to have surgery for now?

About the operation itself

• Which of the steps will you perform, and on one side or both?
• Will you use image guidance, and why or why not for my anatomy?
• Are you planning a septoplasty or turbinate reduction at the same time?
• Which specific risks are higher or lower for me given my scan?

About recovery

• Which of my medicines should I stop or continue, and who will confirm that with the prescribing doctor?
• When and how should I start rinses, and what should the discharge look like?
• How many follow-up visits do you anticipate, and will debridement be part of them?
• What symptoms after surgery would you want me to call about the same day?
• What long-term treatment do you expect me to need afterward?

Bring a companion if you can; two sets of ears catch more. Ask for the plan in writing, including the phone number to call after hours. And if any answer leaves you unsure, it is entirely reasonable to say so and ask for a second appointment before signing consent. The decision sits with you and your treating team, and a good team welcomes the questions.

When to call your doctor after sinus surgery: red-flag signs

Most recovery from FESS is uneventful, and the bloody trickle, congestion and dull ache of the first days are expected. A small number of signs, however, should prompt a same-day call to your surgical team or, where noted, emergency care. These are drawn from the aftercare guidance of Cleveland Clinic and Mayo Clinic.

Seek emergency care immediately if you notice:

• Heavy, continuous bleeding from the nose or down the throat that does not slow with sitting upright and gentle pressure for several minutes.
• Any change in vision, double vision, or sudden swelling and bruising around one eye, particularly if the eye feels tight or is hard to move.
• A steady drip of thin, clear, watery fluid from one nostril, especially when leaning forward, which can signal a cerebrospinal fluid leak.
• Severe headache with a stiff neck, high fever, confusion or drowsiness, which can indicate infection spreading toward the brain.

Call your surgical team the same day for:

• Fever that develops or persists in the days after surgery.
• Pain that is worsening rather than easing after the third day, or pain not controlled by the plan you were given.
• Thick, foul-smelling discharge, or discharge that turns green or yellow and increases.
• Nausea or vomiting that prevents you keeping fluids down.
• Any reaction you suspect is related to a medicine you were given.

When in doubt, call. Surgical teams would far rather hear about a symptom that turns out to be nothing than miss one that mattered. Keep the after-hours number somewhere visible, tell whoever is staying with you what to watch for, and do not drive yourself if you need to be seen urgently.

Frequently asked questions

What happens during FESS in plain language?

A surgeon passes a thin lighted camera through your nostril and, watching a monitor, removes small pieces of bone, swollen lining or polyps that block the natural sinus openings, then widens those openings so mucus can drain. Nothing is cut on the outside of the face. The operation usually takes from under an hour to a few hours depending on how many sinuses are treated, and most people go home the same day.

How long is endoscopic sinus surgery recovery?

Most people return to light or desk work within about one to two weeks, according to Cleveland Clinic, though congestion and crusting can last several weeks and the lining inside the sinuses keeps healing for longer. Strenuous exercise is usually held off until your surgeon clears it. These are typical ranges rather than promises, and your own timeline depends on how extensive the surgery was and how you heal.

Who needs sinus surgery and who should wait?

FESS is generally considered for chronic sinusitis or nasal polyps confirmed on CT scan that have not improved after an adequate course of medical treatment. People with symptoms but a clear scan, those in the middle of an acute infection, those whose headaches likely have another cause such as migraine, and most children are usually asked to wait or are steered toward other options. The decision rests with your ear, nose and throat specialist.

What are the main FESS surgery risks?

The most common issues are minor bleeding, temporary changes in smell, infection and scar tissue that can narrow the new openings. Rare but serious risks include injury to the eye and a cerebrospinal fluid leak from the thin bone beneath the brain, both of which surgeons take specific steps to avoid. Mayo Clinic and Cleveland Clinic list these on consent forms so they can be discussed in relation to your own scan.

Is FESS done under general anesthesia?

Usually, yes. Most adult FESS and virtually all pediatric FESS is performed with the patient fully asleep and a breathing tube protecting the airway. Some limited procedures, such as removing a small polyp or opening a single sinus, may be done under local anesthesia with sedation. The anesthesia team decides based on the planned extent of surgery, your health and your preference.

Will my nose be packed after sinus surgery?

Often not with traditional gauze. Many surgeons now use dissolvable dressings or no packing at all, and when a removable dressing is used it typically stays only a day or two. You will still feel blocked from swelling and clot, and a gauze pad under the nose catches the expected blood-tinged trickle in the first days. Your surgeon will tell you exactly what was placed and when it will dissolve or be removed.

Does FESS help sinus headaches?

Only when the headache is genuinely caused by sinus blockage that appears on a CT scan. Mayo Clinic notes that many people who believe they have sinus headaches actually have migraine, which surgery does not treat. If headache is your main symptom and your scan is clear, your team will usually look for another cause before considering an operation.

Can nasal polyps come back after FESS?

They can. Polyps are a sign of an underlying inflammatory tendency rather than a one-time problem, so removing them does not remove the tendency. Long-term treatment with steroid rinses or sprays after surgery, decided with your ear, nose and throat team, aims to keep regrowth in check, and revision surgery is a recognized part of managing the condition for some people over the years.

Do I still need nasal sprays and rinses after surgery?

In most cases, yes. Surgery reshapes the anatomy so that medicines can reach lining they previously could not, which is one of its main purposes. Saline rinses are usually started within days and steroid treatment is often resumed once healing allows. What you continue, and for how long, is decided by your prescribing clinician based on your diagnosis and how your sinuses look at follow-up.

What is the difference between FESS and balloon sinus dilation?

Balloon dilation widens a natural sinus opening by inflating a small balloon inside it, without removing tissue, and suits selected anatomy without polyps or extensive ethmoid disease. FESS removes obstructing bone, lining or polyps under camera view and can address every sinus, including the honeycomb ethmoid cells a balloon cannot treat. Your surgeon chooses between them based on what your CT scan shows.

References

• Sinusitis (sinus infection), NHS
• Sinusitis, MedlinePlus
• About Sinus Infection, CDC

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.