What’s the difference between a good and bad carbs?

DEAR DOCTOR K: In your column you often distinguish between "good" and "bad" carbohydrates. What makes a carb good or bad?

DEAR READER: Carbohydrates -- carbs -- occur naturally in a variety of foods, from fruits, vegetables and milk, to breads, cereals and legumes. Carbs are also added to many foods, often in the form of sugar. Your digestive system transforms carbs into glucose (blood sugar). They are your body's main source of energy. Whether a carb is "good" or "bad" depends on several factors. Some of the most important are:

Do eating and bowel habits change as we age?

DEAR DOCTOR K: As I've entered my 70s, I've noticed that my eating and bowel habits have changed. Is this normal?

DEAR READER: Well, I could tell you what it says in the medical textbooks, or I could speak from personal experience. The answer would be the same: It sure is normal. Aging most definitely affects our eating and bowel habits. The human digestive system -- our gastrointestinal (GI) tract, or "gut" -- is a series of hollow organs linked to form a long, twisting tube. It begins at the mouth and winds down through the esophagus, stomach, small intestine and colon. These organs break down food into components that the body can absorb and use for energy. What's left is expelled by an efficient disposal system.

Do children who sleep less weigh more?

DEAR DOCTOR K: I recently saw a headline that said children who sleep less weigh more. Is that true? How much sleep should my preschooler and first-grader get each night?

DEAR READER: I believe you're referring to a study recently published in the medical journal Pediatrics. Researchers found that children who don't get enough sleep may also have a higher risk of being overweight. Researchers from Harvard-affiliated Massachusetts General Hospital for Children kept track of more than 1,000 children from the ages of 6 months to 7 years. They asked mothers how much sleep their children got at the age of 6 months, 1 year, and then every year until the end of the study.

Should I request advanced cholesterol testing?

DEAR DOCTOR K: Should I request "advanced" cholesterol testing at my next checkup?

DEAR READER: A standard cholesterol test, or lipid profile, measures levels of HDL, LDL, total cholesterol and triglycerides in the blood. So-called "advanced" cholesterol testing is a more detailed version of this test. Cholesterol is a waxy, yellowish fat. It travels through your bloodstream in tiny, protein-covered particles called lipoproteins. These particles contain cholesterol and triglycerides, a type of fat.

Is there a surgical fix for obstructive sleep apnea?

DEAR DOCTOR K: Is there a surgical fix for sleep apnea? I've tried CPAP and a couple of other treatments, and none of them work well for me.

DEAR READER: Sleep apnea is a condition in which breathing stops intermittently, or becomes shallower, during sleep. Obstructive sleep apnea (OSA) is the most common form. OSA occurs when muscles in the back of your throat relax as you sleep. This causes the airway -- the space in the back of your throat through which air passes when you breathe -- to periodically collapse. If air can't get into your lungs, oxygen levels in your lungs drop, which then causes oxygen levels in your blood to drop.

What is the best treatment for a painful bunion?

DEAR DOCTOR K: I have a painful bunion. What is the best way to treat it?

DEAR READER: A bunion occurs when two bones in your foot no longer line up properly. Normally, a bone in the foot lines up straight with the first bone in your big toe. With a bunion, the joint where those two bones meet no longer is straight. Instead, there's knobby bone bulging outward at the base of your big toe. And the big toe itself turns inward, bending toward, or even under, the other toes. As a result, the knobby bone at the base of your big toe points outward.

Is periodic limb movement disorder and restless leg syndrome the same thing?

DEAR DOCTOR K: Can you discuss periodic limb movement disorder? Is it the same as restless legs syndrome?

DEAR READER: Restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) are similar disorders, and often (but not always) occur together. RLS causes a wide range of uncomfortable leg sensations. They tend to occur most often when the legs are at rest during the day or in the evening. The sensations are almost always accompanied by an irresistible need to move the legs. Moving the legs can bring temporary relief.

Would palliative care help my ailing mother live out her remaining days comfortably?

DEAR DOCTOR K: My mother has advanced cancer and has only a few months to live. How can we help her live out her remaining days with as little pain and as much peace as possible?

DEAR READER: Sadly, as in your mother's case, there are times when cancer takes hold and doesn't let go. In that situation, palliative care can help maintain quality of life and lead to a "good death." Palliative care focuses on both emotional and physical needs. It makes relief of pain and suffering a top priority. It also provides active support to loved ones and caregivers, including information about how to take care of someone at home.

Is it ok that I’ve stopped ejaculating even when I orgasm?

DEAR DOCTOR K: For the past few months, I haven't been ejaculating, even when I have an orgasm. Why not? What's wrong?

DEAR READER: It sounds like retrograde ejaculation. To explain that, we need to talk about anatomy. There is one tube, the urethra, which leads from the bladder and through the center of the penis. The urethra carries urine out of the body. Two tubes, one on each side of the urethra, lead from the seminal vesicles and open into the urethra. The seminal vesicles are tiny glands that make semen. (The prostate gland helps make semen, too). Semen is a thick fluid that helps nourish sperm. Semen really has no other purpose: It is produced onlyto help sperm.

Is my urinary incontinence caused by giving birth vaginally?

DEAR DOCTOR K: I've had urinary incontinence ever since I gave birth last year. Why?

DEAR READER: Many women who give birth vaginally go on to develop loss of bladder control. This is called urinary incontinence. Childbirth can cause two types of incontinence. If urine leaks out when you jump, cough or laugh, or during any activity that puts pressure on your bladder, you have stress incontinence. You have urge incontinence (overactive bladder) if you feel a strong, overwhelming urge to urinate, even when your bladder isn't full. You probably also release some urine before you make it to the bathroom.