Why am I still coughing three weeks after a chest cold?

DEAR DOCTOR K: I had a chest cold. I feel better, but I'm still coughing a lot. This has been going on for more than three weeks. Why am I still coughing?

DEAR READER: Most likely, you had bronchitis, an inflammation of the lining of the bronchial tubes. Bronchitis is usually caused by an infection -- viral or bacterial. The bronchial tubes are air passages connecting the lungs to the windpipe. Bronchitis usually starts with an upper respiratory illness that spreads from the nose and throat down into the airways.

Is it dangerous to have an energy drink everyday?

DEAR DOCTOR K: I have two kids and a high pressure job. I'm always exhausted. Lately, I've been drinking an energy drink in the afternoon to get through the day. My husband thinks this is dangerous. Is he right?

DEAR READER: I'm sure many readers can relate to the mid-afternoon slump. It's no wonder that energy drinks and shots have become the fastest-growing category in the beverage industry. What gives energy drinks their jolt is good old-fashioned caffeine.

Should I have my vitamin D level checked?

DEAR DOCTOR K: I've read several articles about the negative effects of a low blood level of vitamin D, but my doctor said I didn't need to have my level checked. Why not?

DEAR READER: Many of my patients are asking me the same question. Vitamin D has been in the news a lot in recent years, but we still don't have solid answers to many questions, including yours. There is strong evidence that people with a low blood level of vitamin D have higher rates of osteoporosis (thin bones).

Are urgent care centers and emergency rooms the same?

DEAR DOCTOR K: What are urgent care centers? Are they the same as emergency rooms?

DEAR READER: They definitely are not the same. Emergency rooms are for true emergencies -- even though many people go to emergency rooms for quite minor problems. Typically, emergency rooms are attached to hospitals, because patients with true emergencies usually need to be hospitalized after their treatment in the emergency room.

How do I protect myself against diabetic ketoacidosis?

DEAR DOCTOR K: I have had Type 1 diabetes for 20 years. I'm worried I may get ketoacidosis, even though I never have. How do I protect myself?

DEAR READER: You are at risk for ketoacidosis, but the fact that you've never had it is encouraging. It means you're already doing the things you need to do to prevent it. That's important, because diabetic ketoacidosis is a serious complication of Type 1 diabetes. Let's start with a few basics. Type 1 diabetes is often called "insulin-requiring" diabetes.

Is it important to know your heart rate when you’re exercising?

DEAR DOCTOR K: I've seen fitness monitors that track heart rate. Is it important to know your heart rate when you're exercising?

DEAR READER: Whether you're just getting started with an exercise routine or are a committed fitness enthusiast, tracking your heart rate can be helpful. Heart rate monitors -- which instantly tell you how fast your heart is beating -- can help you exercise at the right intensity.

How can I make swallowing pills easier?

DEAR DOCTOR K: I have a hard time swallowing pills. Do you have any suggestions?

DEAR READER: Swallowing pills can be difficult and downright unpleasant. It causes many people to gag, vomit or choke. This can keep people from sticking to their medication routines. A new study published in the Annals of Family Medicine may help. In the article, researchers suggest two techniques to help people improve their ability to swallow pills. (I've put illustrations of both techniques below.)

How do I prevent another kidney stone?

DEAR DOCTOR K: I recently had a very painful kidney stone. What can I do to prevent another?

DEAR READER: First of all, my sympathies: Pain from passing a kidney stone can be as bad as any kind of pain. Kidney stones are hard, chemical deposits that form inside the kidney chambers where urine is collected. Urine passes from the kidney down a narrow tube (the ureter) and into the bladder. If a stone gets carried into the narrow ureter, it can get stuck. This can cause severe pain, bloody urine, nausea and vomiting. If you've had one kidney stone, you're at increased risk for another.

Should I stop drinking if I have chronic pancreatitis?

DEAR DOCTOR K: I have chronic pancreatitis. Will it help to stop drinking at this point? Or is it too late?

DEAR READER: It is never too late to stop further damage to the pancreas, but it may be too late to reverse damage done in the past. However, that's water under the bridge. What you want to do now is stop further damage.

Will running wear my knees out faster?

DEAR DOCTOR K: I'm 68. I've jogged regularly for decades, but I've recently developed a touch of arthritis in my knees. Will continuing to run make my knees wear out faster?

DEAR READER: Having mild arthritis in the knees should not stop you from running. And, in case you were wondering, running probably did not create the problem in the first place.