Diagnosis of Sinusitis
Your doctor will ask about your symptoms. A physical examination will be done. The doctor will often be able to make a diagnosis based on your symptoms and the physical exam.
Infectious Disease Society of America (IDSA) base the diagnosis of acute sinusitis on the presence of certain symptoms. Acute sinusitis will have at least two of the following major symptoms or one major symptom plus two or more minor symptoms:
Major symptoms include:
- Nasal congestion or obstruction
- Facial congestion or fullness
- Facial pain or pressure
- Discharge with pus from nose
- Rear nasal discharge that has pus or is discolored
- Decreased or no ability to smell
Minor symptoms include:
- Ear pain, pressure, or fullness
- Bad breath
- Dental pain
Your doctor may need to decide if a virus or bacteria caused the sinusitis. Infections caused by bacteria may have the following characteristics:
- Signs or symptoms lasting 10 days or more without any signs of improvement
- Worsening signs or symptoms after a period of improvement
- Severe symptoms such as fever 102 degrees Fahrenheit (39 degrees Celsius) or more and nasal discharge with pus that lasts 3-4 consecutive days or more
Other tests may be done in certain situation include:
This simple procedure involves shining a bright light (as from a flashlight) over your cheek in a dark room. If no light illuminates certain areas of your face, then it’s likely that you have a sinus infection. This test, though, is not very reliable and is not commonly performed.
Your doctor might send a sample of your nasal discharge to a laboratory, where it can be tested for the presence of bacteria. Accurate evaluation of a nasal culture usually requires that the culture be obtained during nasal endoscopy. If you are healthy and have acute sinusitis, a nasal culture is usually not done.
X-rays of the sinuses are of limited use for diagnosing the presence of acute sinusitis.
This type of imaging study can be useful for diagnosing sinusitis, including in those areas not well visualized by sinus x-rays. CT scans are particularly effective for diagnosing chronic sinusitis.
Magnetic Resonance Imaging (MRI)
Your doctor may order this test if complications of sinusitis are suspected.
Sweat Chloride Test
Blood Tests for Immune Function
Your doctor may request these tests if you have recurrent or chronic sinusitis.
If there’s some confusion about your diagnosis, your doctor may choose to send you to a specialist to have a sinus puncture performed. This involves using a needle to remove a bit of fluid from within your sinuses. This fluid will then be sent to a lab to identify the infecting bacteria and to determine the most effective type of antibiotic for treatment.
This procedure uses a slim, flexible tube with a fiberoptic light at the end (endoscope). It is inserted into your nose. Your doctor can inspect the mucosa of the nose and the openings of the sinuses. If indicated, he can also take samples or biopsies through the endoscope for lab examination to look for fungus, tumor, or other uncommon cause of your sinusitis.
Last reviewedSeptember 2014by David L. Horn, MD, FACP
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.