Have there been any recent advances in the treatment of polycystic ovary syndrome?

DEAR DOCTOR K: I have polycystic ovary syndrome and treatments are helping only a little. My doctor says there has been recent progress in understanding what causes it, and that I should not give up hope. What is your opinion?

DEAR READER: For readers who don't know about polycystic ovary syndrome (PCOS), I should explain a few things first. PCOS is pretty common: About 10 to 20 percent of women have it to some degree. The key features of this illness are multiple cysts in the ovaries, failure of the ovaries to release eggs (and resulting difficulty getting pregnant), irregular menstrual periods and high levels of androgens.

Do shift workers have an increased risk for health problems

DEAR DOCTOR K: I'm a nurse, and I can be assigned to work the day shift, evening shift or night shift. I hear that shift workers can develop health problems. What is known about that?

DEAR READER: More than 9 million people in the United States are shift workers like you. Studies show that nearly 10 percent of night-shift workers have severe reactions to that schedule. Some become overwhelmingly sleepy during the night shift, when they need to be alert. Some have trouble concentrating and focusing on a task. Others can't really fall deeply asleep during the day, when they need to get some sleep.

Is there a skin patch that can be used to test blood sugar in a person with Type 1 diabetes?

DEAR DOCTOR K: I'm 54 and have had Type 1 "childhood" diabetes since I was 7. A friend with diabetes heard about a new skin patch that automatically keeps a person's blood sugar in control -- no finger-sticks to check blood sugar, no needles for getting insulin. Can that possibly be true?

DEAR READER: It's not true yet, but I think it's coming. I'm glad you asked the question, because what I'll call "electronic skin patches" are starting to affect both medical care and research in many areas, not just diabetes.

Does vaginal estrogen cream pose a risk to my heart health?

DEAR DOCTOR K: Vaginal estrogen cream cures my vaginal dryness. But I hear estrogen is risky for the heart. Should I be concerned?

DEAR READER: Basically, I wouldn't worry. Here's why. Vaginal estrogen cream is one form of hormone therapy (HT). HT is estrogen taken alone or with other female hormones to treat the symptoms of menopause. "Systemic" HT involves hormones that enter the blood and travel throughout the body. It is the most effective treatment for postmenopausal hot flashes and vaginal symptoms, including vaginal dryness.

Is it safe to take an antidepressant during pregnancy?

DEAR DOCTOR K: I have been on SSRI medicines for depression for five years. I'm trying to get pregnant, and I hear that SSRIs might be dangerous. What do I need to know?

DEAR READER: I love to receive questions that I can answer confidently. Yours is not one of them. The evidence from different studies is conflicting. Here's my best attempt to weigh the risks against the benefits.

Is exercise good for the brain?

DEAR DOCTOR K: I do both aerobic exercises and resistance (strength) training exercises. Recently I heard that aerobic exercise might be better for the brain. Is there any truth to that?

DEAR READER: You probably are referring to a study published in February 2016 that got a lot of media attention. Before getting into the details of that study, it's worth talking more about exercise and the brain.

How much sleep do I need?

DEAR DOCTOR K: I average about six hours of sleep each night. How much is enough, and how much do most people get?

DEAR READER: Let's start with how much is enough. Many large studies have found that people who average fewer than seven hours of sleep per night, or more than nine hours, have more health problems. That is, there is an association between "too little" or "too much" sleep and health problems.

Could you discuss the new approach to vaccines that could supposedly revolution immunization?

DEAR DOCTOR K: I heard on television about a possible new vaccine against HIV, Ebola and other terrible viruses. That sounds like very good news, or is it just hype?

DEAR READER: You may well have heard about a new approach to creating vaccines. The approach is called "passive immunization with neutralizing antibodies." It could revolutionize immunization against Ebola and other viruses, including HIV (the virus that causes AIDS) and influenza (flu) viruses.