Have you ever wondered why your doctor looks inside your nose during an exam? When you have a runny nose or congestion, your doctor needs a good look at the source of the problem.

Doctors will look inside your nose as part of a routine physical exam. They will also look inside your nose when they think you may have other problems, such as an infection or allergy. Sometimes they're looking for other sources of your breathing problem, such as a deviated septum. This is a shifting of the wall that divides the nasal cavity into two parts.

The doctor will use a light source with a tool (nasal speculum) that allows a clear view of about 1½ to 2 inches inside your nose if there is no congestion. Here is what your doctor is looking for:

One of the first things your doctor will notice is color. Your doctor may see that:

• Your nasal membranes are pink. Healthy nasal membranes are pink, the same color as healthy gums.
• Your nasal membranes are bluish or pale and look swollen. Then you may have allergic rhinitis. This is an inflammation caused by a nasal allergy. If this is the case, you might have a nasal discharge that is clear or white. Your doctor might prescribe antihistamines or a nasal steroid to reduce the swelling.
• Your nasal membranes are more red than pale. And you have thick, yellow discharge. Then you may have an infection. If your infection affects the nose, throat, and ears and you have no fever or only a slight one, it may be a cold virus. Viruses often move around in the body. Many people will ask for an antibiotic when they have a cold, but antibiotics are not effective in treating viruses. Antibiotics are used to treat bacterial infections. For a viral infection in the nose, doctors can prescribe decongestants to treat the symptoms.

You may have a fever, with soreness around the bridge of your nose and the top of your cheeks. This may be a sinus infection.

Mucus in the sinuses often drains into the nasal passages. When you have a sinus infection, those passages are not able to drain correctly because of inflammation that is present. If your doctor finds that the infection is bacterial, you may need to take an antibiotic to treat it.

Not all nasal problems are caused by allergy and infection. You can be born with a deviated septum or develop one from a broken nose. In either case, the deviated septum can make it hard to breathe through your nose. Sometimes surgery is needed to correct the problem.

When a doctor looks inside your nose, they may notice a nasal polyp. This is a growth on the mucous membrane. Sometimes these polyps must be removed. Some people with sinus disease with recurrent nasal polyps, asthma, and a sensitivity to aspirin or a nonsteroidal anti-inflammatory drug may have a condition called Samter's triad.