What is the most effective way to treat premature ejaculation?

DEAR DOCTOR K: I've been experiencing premature ejaculation. What is the most effective way to treat this?

DEAR READER: Premature ejaculation (PE) occurs when a man reaches orgasm and ejaculates too quickly and without control. In other words, ejaculation occurs before a man wants it to happen. Several factors may contribute to this problem. Diabetes, problems with the thyroid gland or inflammation of the prostate are common culprits. Stress, depression and other emotional factors can also play a role. But most men with PE are healthy.

Does the amount of cholesterol you eat affect the cholesterol levels in your blood?

DEAR DOCTOR K: Does the amount of cholesterol you eat affect the cholesterol levels in your blood?

DEAR READER: I'm glad you asked this question, because I think doctors and the news media have not made it clear. For decades, doctors and food scientists have warned against the dangers of eating foods high in cholesterol. That seemed to make sense. First, high blood levels of so-called "bad" (LDL) cholesterol definitely are bad for your health. Second, it seems logical that the more cholesterol you take into your body when you eat, the higher the cholesterol in your blood. But there's growing agreement among nutrition scientists that cholesterol in food has little effect on cholesterol in the bloodstream.

I have basal cell skin cancer, what will happen during Mohs surgery?

DEAR DOCTOR K: I have basal cell skin cancer on my face and am scheduled to have Mohs surgery. Can you describe what will happen during the procedure?

DEAR READER: Skin cancer is the most common cancer in the United States. Basal cell cancer is a very slow-growing type of skin cancer. It is unlikely to spread to other parts of the body, and therefore is rarely life-threatening. The most common cause of basal cell cancer is damage from sun exposure. Basal cell carcinoma begins in basal cells, which are located deep in the skin. When these basal cells turn cancerous, they invade surrounding tissues, spreading downward and outward below the skin's surface.

What does it mean if my hemoglobin is low?

DEAR DOCTOR K: I'm a 31-year-old woman, and I try to donate blood every couple of months, but the last time I tried, I was turned away because my hemoglobin was too low. What does that mean? And what can I do about it?

DEAR READER: That's terrific that you are a regular blood donor. The American Red Cross says that one pint of blood -- roughly the amount collected during a donation -- can treat an average of three people who need blood. And that treatment can save lives.

Is chocolate actually good for the brain?

DEAR DOCTOR K: Is chocolate really good for the brain?

DEAR READER: It sounds too good to be true, but research has found that certain compounds in chocolate, called cocoa flavonols, may protect brain function. In one recent study, researchers tested the effects of cocoa flavonols in 90 healthy 61- to 85-year-olds with good memory and thinking skills. Participants drank a special brew containing either a low (48 milligrams, or mg), medium (520 mg) or high (993 mg) amount of cocoa flavonols each day.

Can Botox injections help treat chronic migraines?

DEAR DOCTOR K: I suffer from chronic migraine headaches. My doctor mentioned Botox injections as a possible treatment. Can you tell me more?

DEAR READER: I'll bet you were surprised when you told your doctor you needed treatment for your migraines, and he or she said, "You need Botox!" After all, what does removing wrinkles have to do with headaches? Botox can do much more than remove wrinkles. Botox -- short for botulinum toxin -- is a substance made by the bacteria responsible for botulism.

Is coffee bad for your heart health?

DEAR DOCTOR K: I've heard that coffee is good for your health -- but I've also heard that it increases your blood pressure and heart rate. What's true?

DEAR READER: Right now, the evidence I'm aware of points to health benefits for most people from regularly drinking coffee. I'm talking about straight coffee -- minus the cream and sugar. Straight coffee is a nearly calorie-free beverage brimming with antioxidants. There's evidence that drinking coffee might help prevent Type 2 diabetes and reduce the risk of heart disease and stroke. And studies show lower rates of gout and liver disease among regular coffee drinkers.

How can you prevent developing colon polyps?

DEAR DOCTOR K: My young son had rectal bleeding caused by a colon polyp, which the doctor surgically removed. Why did he develop a polyp? Can we do anything to prevent more polyps from forming?

DEAR READER: Colon polyps are growths of tissue inside the colon (large intestine). I've put an illustration of a colon polyp below. Most people think of colon polyps as a problem only for adults, but children also get colon polyps. In fact, they are a relatively common cause of bleeding from the rectum in children.

How do you put in eye drops?

DEAR DOCTOR K: I have dry eye syndrome. My doctor prescribed artificial tears, but I can't manage to get the drops into my eyes. Any advice?

DEAR READER: Dry eye syndrome occurs when your body doesn't produce enough tears. Tears moisten, protect and cleanse our eyes. Without enough tears, your eyes may burn, itch, or feel like there is something gritty in them. Dry eye syndrome can also increase your sensitivity to light and cause excessive tears. Dry eye syndrome is often effectively treated with artificial tears. Available over the counter, they mimic the composition of natural tears. Of course, they work only if you can get them into your eyes. Like you, many people need to learn how to do it.

How do I know if I’m pushing myself too hard while exercising?

DEAR DOCTOR K: I like really intense exercise, so I expect things to hurt when I'm working out. How do I know if I'm pushing myself too hard?

DEAR READER: The expression "no pain, no gain" has misled many an exercise enthusiast. The fact is, pain and other symptoms during exercise are not normal. You should pay attention when your body is sending you warning signs. Let's start with what you should expect. At the height of a workout, you should be breathing a little harder. You should still be able to talk, but you shouldn't be able to sing. You should feel your heart beating faster than normal during exercise. And you may feel your muscles burn a little as they work hard for you.