What is fifth disease and is it contagious?

DEAR DOCTOR K: A child in my son's class has "fifth disease." What is this? Is it contagious? What can I do to prevent my son from catching it?

DEAR READER: Fifth disease, also known as erythema infectiosum, is a common viral infection among school-aged children. It is caused by a virus called parvovirus B19. Fifth disease usually is a mild illness. Some people who are infected with the virus may never realize they have it. When symptoms do occur, they may include a stuffy nose, runny nose, slight fever, or body aches, headache, nausea, diarrhea and fatigue. These symptoms pass after three or four days.

What happens during a bone marrow transplant?

DEAR DOCTOR K: I have leukemia. Thankfully, a family member was a bone marrow match. Can you tell me what to expect during my bone marrow transplant procedure?

DEAR READER: A bone marrow transplant can be a life-saving treatment. To understand how it works, you need to understand how blood cells are created. And what leukemia is. Your blood contains red and white blood cells. There are several types of white blood cells, which are a key part of your immune system. All your blood cells are made by blood stem cells, which live primarily in the spongy center of your big bones.

Can dementia be treated or reversed?

DEAR DOCTOR K: My mother has started showing signs of dementia. Will it be all downhill from here? Or can dementia ever be treated or reversed?

DEAR READER: There are many different causes of dementia. We can't do much to slow or reverse some of them, but we can reverse and even cure others. Dementia is a catchall term. It covers a variety of illnesses that cause memory loss, confusion, changes in personality and declining ability to perform everyday activities.

Do I have Raynaud’s?

DEAR DOCTOR K: When I'm out in the cold, my fingers quickly go from cold to numb and often turn whitish. This goes beyond normal feelings of cold. What could be going on?

DEAR READER: What you're describing -- cold, white (sometimes even bluish), numb fingers -- are the hallmarks of an illness called Raynaud's phenomenon. When I first learned about Raynaud's in medical school, I called it the "almost patriotic" illness. That's because its colors are white, blue and red, in that order: WHITE. When people with Raynaud's go out into cold weather, the first thing that happens is that small arteries in the fingers go into spasm.

How do I switch to a plant-based diet?

DEAR DOCTOR K: I'm trying to shift to a more plant-based diet and have added more fruits and vegetables to my meals and snacks. What's the next step?

DEAR READER: Congratulations! You've already made some healthy changes to your diet. Evidence continues to mount that a plant-based diet -- rich in fruits, vegetables, whole grains and healthy plant oils -- may help reduce the risk of many health concerns, including heart disease, stroke, diabetes and cancer. Adding fresh fruits and vegetables, as you've done, is a great first step. The next step is to incorporate more nuts, seeds and legumes into your meals and snacks.

Is it just fear or an actual phobia?

DEAR DOCTOR K: I have a terrible fear of heights, dogs and public speaking. My sister calls them "phobias" and says I should seek help. How do I know if my fears are normal, or if I need treatment?

DEAR READER: We all have things we worry about or are afraid of. And with most of them, we're right to be fearful. But in people with a phobia, the fear is persistent, excessive and unrealistic. As many as one in 10 people suffer from phobias at some time during their lives.

How can I relieve my knee pain without surgery?

DEAR DOCTOR K: I'm in my 60s. My knees have started to hurt, especially when I'm climbing stairs. Can you recommend any nonsurgical ways to relieve this pain?

DEAR READER: Knee pain is one of the most common reasons for doctor visits. As you get older, knee pain can limit your mobility and take away your independence. The keys to keeping your knees healthy? Strengthening muscles around the knees, improving balance and losing weight.

Can schizophrenia be treated?

DEAR DOCTOR K: There is a history of schizophrenia in my family. I'd like to learn more about it. Can it be treated?

DEAR READER: Schizophrenia is a long-lasting psychotic disorder. People with the condition have a hard time recognizing reality, thinking logically and behaving naturally in social situations. Having a parent or sibling with schizophrenia increases your risk of developing it.

How can I prevent tension headaches?

DEAR DOCTOR K: I get tension headaches fairly often. What's the best way to treat and prevent them?

DEAR READER: Tension headaches are the most common type of headache. The pain -- usually a dull tightness or pressure -- may envelop your entire head, or it may strike only your forehead or the back or top of your head. (I've put an illustration showing where tension headaches usually strike below.)

How do I prepare my preschooler for the arrival of a new baby?

DEAR DOCTOR K: I'm expecting my second baby in a few months. Everyone's excited except my 2-year-old son. What can I do to help my son look forward to the new arrival?

DEAR READER: Your son has always gotten all the attention -- and he probably assumed that he always would. I was the oldest child. My parents told me (many years later) that I wasn't real excited that a new brother or sister was on the way. I find that hard to believe, of course. It's no wonder that your son is not enthusiastic about a noisy, demanding baby that may steal the spotlight.