There are many reasons why your sex life has lapsed into hibernation. To determine why, and what to do about it, consult this nine-point checklist:

For Women

1. PROBLEM: Sex is painful.

   Perhaps you have pain in or around the vagina, during intercourse or otherwise. Maybe you don't lubricate or get as wet as you used to.

   SOLUTION: As you age, your estrogen level diminishes, leading to changes in elasticity in the vagina and the bladder. These changes occur to all women as they age. Hormone therapy, available in a number of forms, including pills, creams and patches, may ease your symptoms. Using a vaginal lubricant or a vaginal ring also can diminish the pain, but addressing the underlying problem -- a reduction in estrogen -- is recommended.

2. PROBLEM: You're too tired for sex.

   Fatigue never used to be a problem. But now it seems as if you are always tired. You're pulled in a dozen directions, and you feel like you have no time for yourself.

   SOLUTION: The hormonal changes brought about by menopause or perimenopause can wreak havoc on your hormone level. Fatigue is one of the primary symptoms of perimenopause or menopause. A drop-off in the production of thyroid hormones also can contribute to feelings of fatigue. Hormonal or nonhormonal therapies may restore your energy levels. Basic lifestyle changes, such as increased exercise and cutting back on caffeine, also can help. Modifications to your sleep habits can be useful, too. In any event, since fatigue can have many causes, you should see your doctor for a proper diagnosis and appropriate treatment.

3. PROBLEM: You're going through perimenopause.

   Perimenopause is a kind of "sneak preview" of menopause. That is, you begin to experience symptoms like hot flashes, vaginal dryness, insomnia, breast tenderness and night sweats, although you may continue to have regular periods. (Some women experience irregular periods.) These symptoms can begin up to five years before the start of menopause, typically any time between 35 and 55.

   SOLUTION: Perimenopause is a time of erratic production of estrogen, Dr. Altman says. "Sometimes you make too much, sometimes too little. Sometimes, it's just right." Talk with your health-care provider. Educating yourself about these normal hormonal changes may help reduce your fears. Hormonal and nonhormonal therapies also can be helpful.

4. PROBLEM: Your hormone therapy isn't working.

   Hormone-replacement therapy can have beneficial effects on cardiovascular disease and osteoporosis, boost your energy levels and ease insomnia. It may also relieve vaginal dryness and pain. On the other hand, it can also give you cramping and breast discomfort. More to the point, it can also reduce testosterone levels, lowering your libido.

   SOLUTION: Hormone-replacement therapy is a very individualized matter. "No two women have the same symptoms," Dr. Altman says. "No one size fits all." Some women benefit from hormones, he says, but some don't. He recommends a discussion with your doctor to determine the best course of action.

5. PROBLEM: You've lost your libido.

   If you've lost your sexual desire, it could be a temporary state of affairs, possibly brought on by stress or relationship issues. Depression also can put the brakes on your libido. In many women, the hormonal changes resulting from perimenopause also can repress desire, as can some medications, such as certain antidepressants.

   SOLUTION: Any number of treatments, including hormonal therapy, can potentially lift your libido. Exercise also is a good sexual stimulant. It raises levels of mood-enhancing hormones and boosts your body image. But if the reason for your repressed desire runs deeper than a temporary lull in the activities, consult with your health-care provider. An adjustment of your existing medications also might be called for.

6. PROBLEM: You have problems with your body image.

   If you're like most of us, you probably don't have the same body you had when you were 22. In fact, a recent study suggests women are 10 times more likely to have a poor body image than men are. This, even though men were more likely to be overweight.

   SOLUTION: "A natural part of aging is a slowing of the metabolism and a shift from the pear to the apple shape," Dr. Altman says. That is, there's a shifting of weight to your lower abdomen. That can cause a distortion of your body image. You are not powerless to change your body, of course, but the question is: Should you? Regardless of your body shape and size, what's important is to learn to accept yourself for who you are. Some of us need extra help in that department, and for that you might consult a health-care practitioner or body-image therapist.

For Men

1. PROBLEM: You don't develop or maintain an erection for as long as you used to, or as well as you used to.

   Age-related performance problems are not unusual, even if you're just as interested in sex as you used to be. Sometimes, male sexual performance can be inhibited by psychological issues, such as depression. But still others relate to physical changes in the blood flow to the penis. And all too often, these changes lead to performance anxiety, which can cripple your sex life.

   SOLUTION: "Fifty percent of men over 50, 60 percent over 60, and 70 percent over 70 have some degree of erectile dysfunction," says Dr. Altman. "This can even be a normal part of aging." A doctor's evaluation is important. Viagra is perhaps the best-known prescription treatment for erectile dysfunction and the resulting performance anxiety. Other options also can be reviewed.

2. PROBLEM: You're just not as interested in sex as you once were.

   Some research suggests that a gradual drop-off in the male hormone, testosterone, may be linked to loss of libido. Some medical experts recommend testosterone therapy, but others question its effectiveness and safety. At the same time, men are no less susceptible to anxiety and depression. You've probably heard it said that the brain is the most important sexual organ, and there's little doubt that your emotional burdens can weigh heavily on your ability to perform sexually. Finally, a side effect of many medications is lowered libido.

   SOLUTION: Medical evaluation and consultation are necessary to determine the underlying cause of your loss of desire. Prescription medications may be effective, and possibly a reevaluation of your existing medications, but you might also benefit from counseling therapy or lifestyle changes.

3. PROBLEM: I'm embarrassed about how much my body has changed.

   Very few of us still can fit easily into our high school letter sweaters. If you're like most of us, you've put on some weight. Maybe you've lost some hair along the way, too. Or perhaps you are concerned that you are not as well-endowed as you imagine other men are.

   SOLUTION: As you age, there are plenty of good reasons for watching what you eat and getting more exercise, and those two steps might help improve your body's shape and enhance your sense of well-being. But if you're going to put off sexual satisfaction until you have regained your Charles Atlas physique, you could be sexually frustrated and miserable for a long time. Your doctor may recommend counseling therapy to help you learn to work through your concerns about body image.