People with allergies who also have a nasal or sinus obstruction experience some of the same frustration as motorists on I-15 at rush hour: Traffic flow is either slow or at a standstill, and you don't know all the reasons why.

That's how Dr. Saurabh Shah, chief of the division of otolaryngology at LDS Hospital, describes how many allergy sufferers experience breathing through their noses, particularly during peak allergy season.

Shah and his colleague, Dr. Joshua Bradley, who is an ear, nose and throat specialist at LDS Hospital, will answer questions about allergies, causes and treatment from 10 a.m. to noon Saturday during the free monthly Deseret News/Intermountain Healthcare Hotline. Call 800-925-8177.

Shah said he expects a challenging year for allergy sufferers, with the weather in Utah unseasonably cool and damp, which feeds the grasses, weeds and trees that produce allergens.

"In Utah, we don't have a lot of molds, but we do have a lot of weeds," he said. "People get hit by trees and grasses in spring and early summer, and then again in August when it gets real hot, the sagebrush and ragweed come out. "

Between 15 percent and 20 percent of the population in general suffer with allergies, Shah said, and in many cases their quality of life is significantly diminished as a result.

Though most allergies are not life-threatening, "sinusitis negatively impacts quality of life more than diabetes, heart disease or asthma," he said. "It's one of the worst things you can have."

In addition to blocked nasal passages, many allergy sufferers have chronic headaches, nasal drainage or coughing when symptoms are out of control.

Often patients are treating their allergies with medication, but they have nasal obstructions that haven't been treated so they don't find relief, Shah said.

Other patients have had surgery for a deviated septum, nasal polyps or to scrape out their sinuses, but they are unaware of their allergies or unable to control them.

Bradley said he often sees patients who say "they just can't breathe through their nose" but don't recognize that they have allergies.

"We test them and often they're positive," he said.

At that point, Bradley prescribes medication, usually beginning with antihistamines and moving into steroid medications if necessary. Those who still suffer become candidates for surgery.

Some patients who are congested on one side during part of the day and congested on the other side later on need turbinate reduction surgery, which shrinks the tissues that project from the lateral wall of the nose into the nasal cavity.