Ask Dr. H: Why there are more colds during winter

Question: Why are colds much more common in the winter?

Answer: It's no coincidence that more colds, more flu, and more sinus infections occur in the winter than at other times of the year.

The nasal lining and the upper respiratory tract are your first barriers against infection. When the air starts to get dry in the fall, the house starts to dry out. It pulls moisture into the walls, ceiling, and floor, causing you to dry out too.

Furnace heat dries the air out even more. The first thing you notice is a stuffy nose. As the nasal tissues dry out and become thin, tiny capillaries in your nose are exposed, causing blood-tinged mucus when you blow your nose.

The next thing that happens is that body tissues dry out further, revealing cracks and defects in the lining of the nose and upper respiratory tract. Those cracks allow viruses and bacteria to penetrate and make you sick.

There's a natural cyclical pattern where there are more viruses in the air now than in the summer. We're indoors more, surrounded by more people who are sick.

What can we do? First of all, be sure to use home humidifiers during the winter months to keep those tissues in the nose and upper airway from drying out.

Other things that will help: good hand-washing; adequate sleep; good nutrition and hydration; correcting a low blood level of Vitamin D; and limiting close contact with those folks who might be sneezing or coughing.

Q: I have had a frustrating problem with a bitter taste in my mouth for the past year. I've seen many doctors and my dentist about it. I've tried vitamins with zinc, and I've even eliminated my medications one at a time for 15 days apiece - all to no avail. I've tried mouthwashes, candies, and antacids without help. I started dialysis almost a year ago and the bitter taste started a little before that. Is there anything that you can recommend to eliminate this taste?

A: I wish that there was something that I could suggest, but the reason you're having that bitter taste (some describe a metallic taste sensation) is because of severe chronic kidney disease. The job of the kidneys is to get rid of waste products, and in your case, there's a buildup because the kidneys are functioning poorly - so poorly that you now require dialysis treatments to filter your blood.

In a healthy state, the kidneys are working around the clock to keep waste products from building up in the blood. Dialysis treatments are nowhere near as effective as a healthy set of kidneys.

You mentioned in your letter that on some days, the taste is stronger than others. I would expect that your symptoms are probably at their worst when you're due for dialysis and they improve within hours after your dialysis treatment. I'm not aware of any kinds of masking agents that will help you, but maybe your nephrologist can help by better treating the underlying cause.