Sinusitis, NIAID Fact Sheet: NIAID
Article title: Sinusitis, NIAID Fact Sheet: NIAID
Conditions: Sinusitis, sinuses (see Sinusitis)
What is sinusitis?
You're coughing and sneezing and tired
and achy. You think that you might be getting a cold. Later, when
the medicines you've been taking to relieve the symptoms of the
common cold are not working and you've now got a terrible headache,
you finally drag yourself to the doctor. After listening to your
history of symptoms, examining your face and forehead, and perhaps
doing a sinus X-ray, the doctor says you have sinusitis.
Sinusitis simply means your sinuses are infected or
inflamed, but this gives little indication of the misery and pain
this condition can cause. Health care experts usually divide
sinusitis cases into
- Acute, which lasts for 3 weeks or less
- Chronic, which usually lasts for 3 to 8 weeks but can continue
for months or even years
- Recurrent, which is several acute attacks within a year
Health care experts estimate that 37 million Americans are
affected by sinusitis every year. Health care workers report 33
million cases of chronic sinusitis to the U.S. Centers for Disease
Control and Prevention annually. Americans spend millions of dollars
each year for medications that promise relief from their sinus
What are sinuses?
Sinuses are hollow air spaces in the human
body. When people say, "I'm having a sinus attack," they usually are
referring to symptoms in one or more of four pairs of cavities, or
sinuses, known as paranasal sinuses
. These cavities,
located within the skull or bones of the head surrounding the nose,
- Frontal sinuses over the eyes in the brow area
- Maxillary sinuses inside each cheekbone
- Ethmoid sinuses just behind the bridge of the nose
and between the eyes
- Sphenoid sinuses behind the ethmoids in the upper
region of the nose and behind the eyes
Each sinus has an
opening into the nose for the free exchange of air and mucus, and
each is joined with the nasal passages by a continuous mucous
membrane lining. Therefore, anything that causes a swelling in the
nose-an infection, an allergic reaction, or an immune reaction-also
can affect the sinuses. Air trapped within a blocked sinus, along
with pus or other secretions, may cause pressure on the sinus wall.
The result is the sometimes intense pain of a sinus attack.
Similarly, when air is prevented from entering a paranasal sinus by
a swollen membrane at the opening, a vacuum can be created that also
What are the symptoms of sinusitis?
The location of your
sinus pain depends on which sinus is affected.
- Headache when you wake up in the morning is typical of a sinus
- Pain when your forehead over the frontal sinuses is touched
may indicate that your frontal sinuses are inflammed.
- Infection in the maxillary sinuses can cause your upper jaw
and teeth to ache and your cheeks to become tender to the touch.
- Since the ethmoid sinuses are near the tear ducts in the
corner of the eyes, inflammation of these cavities often causes
swelling of the eyelids and tissues around your eyes, and pain
between your eyes. Ethmoid inflammation also can cause tenderness
when the sides of your nose are touched, a loss of smell, and a
- Although the sphenoid sinuses are less frequently affected,
infection in this area can cause earaches, neck pain, and deep
aching at the top of your head.
Most people with
sinusitis, however, have pain or tenderness in several locations,
and their symptoms usually do not clearly indicate which sinuses are
Other symptoms of sinusitis can include
- A cough that may be more severe at night
- Runny nose (rhinitis) or nasal congestion
the drainage of mucus from the sphenoids or other sinuses down the
back of your throat (postnasal drip) can cause you to have a sore
throat. Mucus drainage also can irritate the membranes lining your
larynx (upper windpipe). Not everyone with these symptoms, however,
On rare occasions, acute sinusitis can result
in brain infection and other serious complications.
What are some causes of acute sinusitis?
Most cases of
acute sinusitis start with a common cold, which is caused by a
virus. These viral colds do not cause symptoms of sinusitis, but
they do inflame the sinuses. Both the cold and the sinus
inflammation usually go away without treatment in 2 weeks. The
inflammation, however, might explain why having a cold increases
your likelihood of developing acute sinusitis. For example, your
nose reacts to an invasion by viruses that cause infections such as
the common cold or flu by producing mucus and sending white blood
cells to the lining of the nose, which congest and swell the nasal
When this swelling involves the adjacent mucous
membranes of your sinuses, air and mucus are trapped behind the
narrowed openings of the sinuses. When your sinus openings become
too narrow, mucus cannot drain properly. This increase in mucus sets
up prime conditions for bacteria to multiply.
people harbor bacteria, such as Streptococcus pneumoniae
and Haemophilus influenzae
, in their upper respiratory
tracts with no problems until the body's defenses are weakened or
drainage from the sinuses is blocked by a cold or other viral
infection. Thus, bacteria that may have been living harmlessly in
your nose or throat can multiply and invade your sinuses, causing an
acute sinus infection.
Sometimes, fungal infections can
cause acute sinusitis. Although fungi are abundant in the
environment, they usually are harmless to healthy people, indicating
that the human body has a natural resistance to them. Fungi, such as
, can cause serious illness in people whose
immune systems are not functioning properly. Some people with fungal
sinusitis have an allergic-type reaction to the fungi.
Chronic inflammation of the nasal passages also can lead to
sinusitis. If you have allergic rhinitis or hay fever, you can
develop episodes of acute sinusitis. Vasomotor rhinitis, caused by
humidity, cold air, alcohol, perfumes, and other environmental
conditions, also may be complicated by sinus infections.
Acute sinusitis is much more common in some people than in
the general population. For example, sinusitis occurs more often in
people who have reduced immune function (such as those with immune
deficiency diseases or HIV infection) and with abnormality of mucus
secretion or mucus movement (such as those with cystic fibrosis).
What causes chronic sinusitis?
If you have asthma, an
allergic disease, you may have frequent episodes of chronic
If you are allergic to airborne allergens, such
as dust, mold, and pollen, which trigger allergic rhinitis, you may
develop chronic sinusitis. In addition, people who are allergic to
fungi can develop a condition called "allergic fungal sinusitis."
If you are subject to getting chronic sinusitis, damp
weather, especially in northern temperate climates, or pollutants in
the air and in buildings also can affect you.
sinusitis, you might develop chronic sinusitis if you have an immune
deficiency disease or an abnormality in the way mucus moves through
and from your respiratory system (e.g., immune deficiency, HIV
infection, and cystic fibrosis). In addition, if you have severe
asthma, nasal polyps (small growths in the nose), or a severe
asthmatic response to aspirin and aspirin-like medicines such as
ibuprofen, you might have chronic sinusitis often.
How is sinusitis diagnosed?
Because your nose can get
stuffy when you have a condition like the common cold, you may
confuse simple nasal congestion with sinusitis. A cold, however,
usually lasts about 7 to 14 days and disappears without treatment.
Acute sinusitis often lasts longer and typically causes more
symptoms than just a cold.
Your doctor can diagnose
sinusitis by listening to your symptoms, doing a physical
examination, and taking X-rays, and if necessary, an MRI or CT scan
(magnetic resonance imaging and computed tomography).
How is sinusitis treated?
After diagnosing sinusitis and
identifying a possible cause, a doctor can suggest treatments that
will reduce your inflammation and relieve your symptoms.
have acute sinusitis, your doctor may recommend
- Decongestants to reduce congestion
- Antibiotics to control a bacterial infection, if present
- Pain relievers to reduce any pain
You should, however,
use over-the-counter or prescription decongestant nose drops and
sprays for only few days. If you use these medicines for longer
periods, they can lead to even more congestion and swelling of your
If bacteria cause your sinusitis,
antibiotics used along with a nasal or oral decongestant will
usually help. Your doctor can prescribe an antibiotic that fights
the type of bacteria most commonly associated with sinusitis.
Many cases of acute sinusitis will end without antibiotics.
If you have allergic disease along with infectious sinusitis,
however, you may need medicine to relieve your allergy symptoms. If
you already have asthma then get sinusitis, you may experience
worsening of your asthma and should be in close touch with your
In addition, your doctor may prescribe a steroid
nasal spray, along with other treatments, to reduce your sinus
congestion, swelling, and inflammation. Chronic
Doctors often find it difficult to
treat chronic sinusitis successfully, realizing that symptoms
persist even after taking antibiotics for a long period. In general,
however, treating chronic sinusitis, such as with antibiotics and
decongestants, is similar to treating acute sinusitis.
people with severe asthma have dramatic improvement of their
symptoms when their chronic sinusitis is treated with antibiotics.
Doctors commonly prescribe steroid nasal sprays to reduce
inflammation in chronic sinusitis. Although doctors occasionally
prescribe them to treat people with chronic sinusitis over a long
period, they don't fully understand the long-term safety of these
medications, especially in children. Therefore, doctors will
consider whether the benefits outweigh any risks of using steroid
If you have severe chronic sinusitis, your
doctor may prescribe oral steroids, such as prednisone. Because oral
steroids are powerful medicines and can have significant side
effects, you should take them only when other medicines have not
Although home remedies cannot cure sinus infection,
they might give you some comfort.
- Inhaling steam from a vaporizer or a hot cup of water can
soothe inflamed sinus cavities.
- Saline nasal spray, which you can buy in a drug store, can
- Gentle heat applied over the inflamed area is comforting.
When medical treatment fails, surgery may be the only
alternative for treating chronic sinusitis. Research studies suggest
that the vast majority of people who undergo surgery have fewer
symptoms and better quality of life.
In children, problems
often are eliminated by removal of adenoids obstructing nasal-sinus
Adults who have had allergic and infectious
conditions over the years sometimes develop nasal polyps that
interfere with proper drainage. Removal of these polyps and/or
repair of a deviated septum to ensure an open airway often provides
considerable relief from sinus symptoms.
The most common
surgery done today is functional endoscopic sinus surgery, in which
the natural openings from the sinuses are enlarged to allow
drainage. This type of surgery is less invasive than conventional
sinus surgery, and serious complications are rare.
How can I prevent sinusitis?
Although you cannot prevent
all sinus disorders-any more than you can avoid all colds or
bacterial infections-you can do certain things to reduce the number
and severity of the attacks and possibly prevent acute sinusitis
from becoming chronic.
- You may get some relief from your symptoms with a humidifier,
particularly if room air in your home is heated by a dry
- Air conditioners help to provide an even temperature.
- Electrostatic filters attached to heating and air conditioning
equipment are helpful in removing allergens from the air.
If you are prone to getting sinus disorders, especially if
you have allergies, you should avoid cigarette smoke and other air
pollutants. If your allergies inflame your nasal passages, you are
more likely to have a strong reaction to all irritants.
you suspect that your sinus inflammation may be related to dust,
mold, pollen, or food-or any of the hundreds of allergens that can
trigger an upper respiratory reaction-you should consult your
doctor. Your doctor can use various tests to determine whether you
have an allergy and its cause. This will help you and your doctor
take appropriate steps to reduce or limit your allergy symptoms.
Drinking alcohol also causes nasal and sinus membranes to
If you are prone to sinusitis, it may be
uncomfortable for you to swim in pools treated with chlorine, since
it irritates the lining of the nose and sinuses.
often get sinus congestion and infection when water is forced into
the sinuses from the nasal passages.
You may find that air
travel poses a problem if you are suffering from acute or chronic
sinusitis. As air pressure in a plane is reduced, pressure can build
up in your head blocking your sinuses or eustachian tubes in your
ears. Therefore, you might feel discomfort in your sinus or middle
ear during the plane's ascent or descent. Some doctors recommend
using decongestant nose drops or inhalers before your flight to
avoid this problem.
What research is going on?
Scientific studies have shown a
close relationship between having allergic rhinitis and chronic
sinusitis. In fact, some studies state that up to 80 percent of
adults with chronic sinusitis also had allergic rhinitis. There is
also an association between asthma and sinusitis. Some researchers
think that as many as 75 percent of people with asthma also get
sinusitis. The National Institute of Allergy and Infectious Diseases
(NIAID) conducts and supports research on allergic diseases as well
as bacteria and fungus that can cause sinusitis. This research is
focused on developing better treatments and ways to prevent these
Scientists supported by NIAID and other
institutions are investigating whether chronic sinusitis has genetic
causes. They have found that the alterations in genes which cause
cystic fibrosis may also contribute to chronic sinusitis. This
research focus will give scientists new insights into the cause of
the disease in some people and points to new strategies for
diagnosis and treatment.
Another NIAID-supported research
study is trying to determine whether fungi may play a role in
causing many cases of chronic sinusitis. This research also will
help scientists develop better medicines to treat chronic sinusitis.
Where can I get more information about
National Library of
American Academy of Allergy, Asthma and Immunology
East Wells Street
Milwaukee, WI 53202
Joint Council of Allergy, Asthma, and Immunology
Brockway, Suite 3.3
Palatine, IL 60067
(847) 934-1918 https://www.jcaai.org/
Academy of Otolaryngology-Head and Neck Surgery, Inc.
Alexandria, VA 22314-3357
NIAID is a component of the National Institutes
of Health (NIH). NIAID supports basic and applied research to
prevent, diagnose, and treat infectious and immune-mediated
illnesses, including HIV/AIDS and other sexually transmitted
diseases, tuberculosis, malaria, autoimmune disorders, asthma and
Press releases, fact sheets and other
NIAID-related materials are available on the NIAID Web site at https://www.niaid.nih.gov/default.htm.
Office of Communications and
National Institute of Allergy and Infectious
National Institutes of Health
Bethesda, MD 20892
U.S. Department of Health and Human Services
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