What is the best way to treat blisters?

DEAR DOCTOR K: I wore a new pair of hiking boots on my vacation and now have several painful blisters on my feet. What's the best way to treat them?

DEAR READER: It sounds like you have friction blisters. A friction blister is a soft pocket of raised skin filled with clear fluid, caused by irritation from continuous rubbing or pressure. The irritation -- in your case caused by new hiking boots -- slightly damages the skin. The uppermost layer of skin separates from the layer beneath, and fluid accumulates in the space that's left.

What’s the difference between an essential tremor and Parkinson’s?

DEAR DOCTOR K: My father was recently diagnosed with essential tremor. Is this the same thing as Parkinson's disease? If not, what is the difference?

DEAR READER: Essential tremor is a brain condition that causes tremors: uncontrollable shaky movements of the hands, limbs, head or voice. It is usually mild and is very common, often running in families. It usually starts later in life, but when it runs in families it can start in young adulthood. In contrast, Parkinson's disease is a serious neurological condition that also causes a tremor.

What happens when someone having a heart attack gets to the hospital?

DEAR DOCTOR K: Can you tell me what happens when someone having a heart attack gets to the hospital?

DEAR READER: You're going about your day when you suddenly start to sweat and become short of breath. You feel a crushing pressure in your chest. You think: "This is it. I'm having a heart attack." A heart attack occurs when one of the coronary arteries, blood vessels that supply the heart, becomes fully or partially blocked.

Has antibiotic use in meat and poultry contributed to antibiotic resistance?

DEAR DOCTOR K: In a recent column on antibiotics, you didn't mention their use in meat and poultry as a cause of antibiotic resistance. Hasn't this contributed to the problem?

DEAR READER: You're correct. In the United States, food-producing animals such as cattle and poultry are regularly treated with antibiotics. This has contributed to antibiotic resistance: bacteria that are no longer susceptible to antibiotics. How do bacteria become resistant? Let's say you take penicillin to treat a bacterial infection.

What causes low blood pressure?

DEAR DOCTOR K: Recently, my blood pressure has been low. I feel tired and dizzy. What could be causing this and what can I do?

DEAR READER: Low blood pressure is not considered a problem unless, as in your case, it causes symptoms. In fact, if it is not causing symptoms, low blood pressure can be a good thing. The typical symptoms caused by low blood pressure include weakness and dizziness, which can increase your risk of fainting and falling. If a person who did not previously have low blood pressure develops it, and has weakness and dizziness, he or she could be developing a heart problem.

Do I need the shingles vaccine if I’ve already had shingles?

DEAR DOCTOR K: I've already had shingles. Do I still need to get a shingles vaccine?

DEAR READER: Shingles is caused by the same virus that causes chickenpox. Once you have had chickenpox, the skin changes of chickenpox go away, but the virus that caused it remains alive inside your nerves. It is inactive, but it can be reactivated later in life. This causes shingles.

What causes gout?

DEAR DOCTOR K: What caused my gout? Will avoiding certain foods prevent flare-ups?

DEAR READER: Gout is a painful joint condition. I know, because I've suffered from it. I spoke to my Harvard Medical School colleague, rheumatologist Dr. Robert Shmerling, to get the latest information. Gout attacks come on suddenly, with sharp pain, often in a single joint. The big toe is a common target.

How much weight should a woman gain during pregnancy?

DEAR DOCTOR K: I am pregnant, and my doctor says that I'm gaining too much weight. I trust the doctor, but I've heard that it's normal to gain weight during pregnancy. How much weight should a woman gain?

DEAR READER: It's natural for a woman's appetite to increase during pregnancy. This is nature's way of making sure that she eats enough for herself and her growing baby. All women should gain weight during pregnancy, while eating healthfully and sensibly. But too much weight gain isn't good for a woman or her baby.

Does eating several smaller meals help with weight loss?

DEAR DOCTOR K: Does eating several smaller meals throughout the day rather than three larger meals help with weight loss?

DEAR READER:We know that eating fewer calories is important to losing weight, but there is less agreement on the specifics. Are three meals a day best for weight loss? Or is it better to eat more -- or less -- frequently? We can rule out eating fewer than three times a day. You'll feel hungry, making it more likely that you will overeat and choose less healthy foods when you do eat.

What can I do to improve my brittle nails?

DEAR DOCTOR K: As I've gotten older, my fingernails have become very brittle. They chip, break and split easily. I've also noticed ridges. What can I do?

DEAR READER: Many of my patients notice that their fingernails become thinner, more brittle and fragile with age. Nails may split lengthwise, or separate in thin layers at the tips. The nails may look different as well. They may become yellowed or dull, and many develop thin, vertical ridges.