DEAR DR. DONOHUE: My voice has been hoarse for a little more than three weeks. I feel fine, and I think this is nothing more than laryngitis. I’m resting my voice by talking as little as possible and whispering when I do. My wife insists I should see a doctor. Do you think this is necessary? – K.D.

ANSWER: Emphatically I do. And stop whispering. It’s a greater strain on your vocal cords than normal speech is.

Laryngitis is an inflammation of the larynx (LAIR-inks), a box-shaped cartilage structure that contains the vocal cords, which vibrate to produce sound as air rushes by them. Inflammation takes place on the vocal cords and causes the voice to assume a rasping quality. The major cause of this inflammation is viral infection.

A run-of-the-mill case of laryngitis lasts about two weeks. When hoarseness lasts longer than that, a person must seek help for conditions that can be serious.

The most fearsome is, of course, cancer. Laryngeal cancer is more common in men, and it often comes on in the 60s or 70s. Smoking and alcohol abuse are sometimes prominent factors in its appearance. As with any cancer, early discovery and treatment yield the greatest success.

Doctors have instruments with which they can get a clear view of all the larynx structures and can often take a biopsy while inspecting them.

Another common and less-threatening cause of hoarseness is a polyp, a pea-sized growth that imparts an unnatural quality to the voice. Voice rest and time can lead to polyp regression in some cases, but in others removal is necessary.

Spastic dysphonia is another condition that causes a strained, faint and tremulous voice. It’s due to involuntary and sustained contractions of muscles that regulate vocal cord movement. Injection of those muscles with Botox can relax them and return the voice to normal.

DEAR DR. DONOHUE: My mother is 84 and lives alone. She is quite active and competent. She complains of itchy skin. I have gone over her entire body and cannot find any rash or unusual changes. Would more frequent bathing help? She takes only one bath a week. – L.P.

ANSWER: Dry skin is the No. 1 cause of itchy skin. More baths would make matters worse. One a week is enough for cleanliness unless you can detect body odor.

She should use a mild soap, and she ought to pat herself with a towel after bathing, leaving a film of moisture on the skin. Then she should apply a moisturizer over the slightly damp skin. She will need help to get it on her back.

Have her change the detergent she uses to wash her clothes.

An antihistamine can sometimes quiet the itch. Many antihistamines make people drowsy, so she should take a dose only once a day before going to sleep, and only if it is compatible with other medications she is taking.

If 10 days of treatment do not stop the itch, then take your mother to the doctor. There are illnesses for which itching is a prominent symptom. Diabetes, cancer of the lymph nodes, kidney failure, liver problems and thyroid malfunctions are examples.

DEAR DR. DONOHUE: My 1-year-old has a bump on the side of his neck near the bottom. His pediatrician calls it a bronchial cyst but does not mention treatment or cause. Would you fill in some of the details for me? – R.R.

ANSWER: I am quite certain your doctor said branchial cyst, not bronchial. Everyone is familiar with “bronchial,” but few are with “branchial.” The mistake is common.

During early development, the embryo has slits in its neck, similar to fish gills. Around the seventh week of development, the slits seal off. Sometimes the seal is not complete, and a cyst remains. If it becomes infected or is very large, it is not much trouble to remove it.

DEAR DR. DONOHUE: I ride a stationary bike five times a week for 20 minutes. I also do leg lifts and isometric exercise. I never hear about the benefits of bike riding. All I hear is advice on walking. Am I not getting any exercise on the bike? I am 82. – J.D.

ANSWER: You are getting plenty of exercise for your heart and blood pressure on a stationary bike. Keep with it.

Where jogging and walking have an edge over a stationary bike is in osteoporosis prevention. To build strong bones, the exercise must be “weight-bearing” exercise, exercise where the skeleton supports body weight. Seated on a stationary bike, you are engaged in “weight-supported” exercise. Your leg lifts and isometric exercise are taxing your bones, so you have the best of all worlds.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.