DEAR DR. DONOHUE: I have been told I have COPD, and I have also been told I have chronic bronchitis. Are they the same? Someone once said I have emphysema. Where does that fit in? – Confused

ANSWER: COPD – chronic obstructive pulmonary disease – is a term for the two main lung illnesses: emphysema and chronic bronchitis. They aren’t the same, but they are frequently found together and often result from cigarette-smoking.

Emphysema is a destruction of the millions of tiny air sacs within the lungs. Oxygen from inhaled air diffuses into the blood through those air sacs, and carbon dioxide, a waste product of body metabolism, flows into the air sacs to be exhaled. A person with emphysema can’t ever get enough air. That person is constantly short of breath and pants while doing the slightest physical activity.

Chronic bronchitis is an inflammation of airways – the bronchi. Irritated, inflamed airways fill with thick mucus and then narrow. The primary symptom of chronic bronchitis is a cough with the production of thick phlegm.

The distinction is important, for if a person predominately has chronic bronchitis, then treatment is directed toward cleaning out the airways and dilating them. Bronchodilators – medicines often used for asthma – are also used to dilate bronchitic airways. Sometimes, as in asthma, bronchodilators are combined with cortisone drugs, which reduce airway irritation and mucus production.

When bronchitis worsens, as it often does throughout the year, an aggressive program of antibiotics is begun. Mucus-filled airways are the ideal breeding ground for bacteria.

Pulmonary-rehabilitation programs are sponsored by many hospitals, and they can demonstrate the techniques used to drain airways of mucus. Ask your doctor if there are any local programs.

The booklet on chronic obstructive pulmonary disease describes both emphysema and bronchitis and their treatments. Readers can obtain a copy by writing: Dr. Donohue – No. 601, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: My wife has multiple sclerosis. She is also taking Lipitor for high cholesterol. I read the information from the pharmacy on Lipitor, and it says the medicine can cause muscle pain and muscle weakness. Should someone with MS be taking this drug? Could it contribute to her muscle weakness? – J.O.

ANSWER: The “sclerosis” of multiple sclerosis stands for scars scattered throughout the brain and spinal cord. Those scars interrupt the transmission of nerve signals to muscles. That’s the cause of the muscle weakness in MS.

Lipitor and the other statin drugs – the most powerful cholesterol-lowering drugs available – only rarely affect muscles. When they do so, they affect muscles directly. They do not affect the nerve connections to muscles.

It is not likely that the Lipitor would have any effect on multiple sclerosis.

DEAR DR. DONOHUE: I detect what I call my heart missing a beat every now and then. I have an annual physical and have had ECGs every year. My doctor says there’s nothing wrong with my heart. What do you think it is I feel? – J.B.

ANSWER: My guess is that those missing beats are really premature ventricular contractions – PVCs. A PVC is an extra beat that arrives before the next programmed beat. You don’t feel it. But after a PVC, there is a longer delay before the next beat, and the heart fills with a greater amount of blood.

When the normal beat arrives with an overfilled heart, you do feel that beat. It’s like a light thud in the chest. Many people call it a skipped beat.

Most of the time, PVCs are harmless and can be ignored. Your doctor has given you yearly exams and has found nothing wrong on your ECGs. You can believe him when he tells you your heart is healthy.

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. Readers may also order health newsletters from www.rbmamall.com.