Should I be worried about lead in my drinking water?

DEAR DOCTOR K: Like a lot of people, I was shocked by the water disaster in Flint, Michigan. I felt terrible for those people. But then I started to wonder: How safe is my drinking water? Should I be worried?

DEAR READER: The sad answer to your question is that I don't know, and neither may your local department of public health.

How can I protect my daughter from lead poisoning?

DEAR DOCTOR K: A friend's daughter got lead poisoning from paint in her house. What can I do to protect my kids?

DEAR READER: Lead is poison. Although major strides have been made in the past 50 years, lead poisoning is unfortunately still a problem. All of us are exposed to lead, but children are most vulnerable to it.

Should I throw out expired medications?

DEAR DOCTOR K: Sometimes the pills in my medicine cabinet reach the expiration date. Do I really need to throw them out? They can be expensive.

DEAR READER: The two questions to ask about pills that are past their expiration date are: Do they lose their strength, and do they become toxic or harmful? There is little evidence that outdated medications become toxic or harmful. However, some drugs do lose their potency, or effectiveness, over time. The most notable is nitroglycerin, which should be replaced every six months.

How can we prevent brain damage during contact sports?

DEAR DOCTOR K: My kids play contact sports. After all the news about how repeated concussions might cause permanent brain damage, I'm worried. Do doctors understand why the brain damage occurs and how to prevent it?

DEAR READER: People have known for a long time that boxers could develop difficulty with thinking, remembering, balance and mood following the end of their careers. The term "punch-drunk" was often used. After all, they're getting hit in the head constantly and are often knocked unconscious.

Should you still eat fish even if there’s a chance you could get mercury poisoning?

DEAR DOCTOR K: I've been hearing for years that eating fish is healthy. But I also hear that mercury and other poisons can be in fish. I like the taste of fish, but should I seek it or avoid it?

DEAR READER: Questions from readers so often ask about the benefits versus the risks of lifestyle practices, or medical tests and treatments. That's because most things have both benefits and risks -- and eating fish is no exception. Fish ranks way up there on the list of healthful foods we should be eating.

How can start a safe stretching routine?

DEAR DOCTOR K: At my last appointment, my doctor noticed that my movements have become stiffer. He suggested that I do some stretching exercises daily. Is there anything I should know before I start? I'm in my 80s, and I don't want to hurt myself.

DEAR READER: Our bodies become less flexible as the years roll by. Inflexibility puts a crimp in daily acts, making it harder to walk, raise your arms or turn your head while backing up the car. It undermines balance, too, which can cause life-altering falls. Stretching can help. You'll make the best gains if you stretch frequently -- all or most days of the week. At the very least, stretch two or three times a week.

What should I look for in mosquito repellents?

DEAR DOCTOR K: Which ingredients should I look for in a mosquito repellent? Are there any I shouldn't use on my kids?

DEAR READER: Ah, summer. Time for relaxing, playing outside, going to the beach -- and mosquitoes. The itchiness from the bites can be maddening. And these tiny, annoying insects can carry serious illnesses, such as West Nile virus and Eastern equine encephalitis.

What should I know about traveling during pregnancy?

DEAR DOCTOR K: My job requires a lot of travel, and I recently became pregnant with my first child. What do I need to know about traveling safely during pregnancy?

DEAR READER: Being pregnant doesn't mean you have to stay at home for nine months. There are exceptions; particularly in the last three months, some women develop complications of pregnancy that require them to be resting. But for most women, travel poses no threat to the mother or child. But travel by car, train or airplane can be less comfortable when you're pregnant, so you should take a few precautions to travel comfortably and safely.

Who should NOT get the shingles vaccine?

DEAR DOCTOR K: You've written about who should get the shingles vaccine, and why. Are there any groups of people who should not get the shingles vaccine?

DEAR READER: I'm glad you asked because, yes, there are groups of people who should not get the vaccine. Shingles is a painful skin rash, often with blisters, that lasts from two to four weeks. Its main symptom is pain, which can be quite severe. For some people, the severe pain of shingles continues long after the rash clears up. Called post-herpetic neuralgia, this condition can last for months, or even years. It can be quite debilitating.

Is there a new way to perform CPR?

DEAR DOCTOR K: I thought CPR involved chest compressions, breathing into a person's mouth and checking their pulse. But my daughter told me that the "new" CPR involves only chest compressions. Is this correct?

DEAR READER: That's right. Since 2008, the American Heart Association has recommended "hands only" cardiopulmonary resuscitation (CPR) if an adult suddenly collapses. Cardiac arrest is usually to blame when someone collapses and stops breathing. It occurs when the heart's electrical system malfunctions. The heart beats rapidly and chaotically -- or stops beating altogether. The person stops breathing and becomes unresponsive.