Dear Dr. Ruth: I’m writing to you for my sister. (I’m sure you’ve heard that one before.) She asked for my help in finding an answer to something I’ve never heard of or experienced. She’s 73 and in her second marriage. Her husband is 64 but has a lot less energy than she does and is snoring by 7:30 p.m.

This is her problem: She says that every four or five months, she’ll be sleeping and then wake up in a cold sweat, “feeling like she has had good sex.” It scares her and she looks around thinking she’ll find someone in her room (she and her husband have had separate bedrooms for the past 19 years). She had a bad experience with a doctor and hasn’t been to a gynecologist since. She lives far from me, otherwise I would bind and gag her and drag her to mine.

Dear Reader: While it’s always a good idea to go for a checkup, which is why I think your sister should visit a gynecologist, she doesn’t need one for this particular “problem.” What’s happening to her is that she’s having an orgasm in her sleep, and there’s absolutely nothing wrong with that. While the idea of a “wet dream” might be more commonly associated with males, many women have orgasms in their sleep as well. These nocturnal orgasms might stem from being sexually frustrated, and so masturbating might eliminate them. But basically, she doesn’t have to do anything at all or look around to see if anyone is in her room. It’s a natural occurrence and she should accept whatever positive feelings she gets from these orgasms.

Dear Dr. Ruth: I have had a sexual relationship for more than a year with a healthy 54-year-old man. I consider him an excellent sexual partner. He has no trouble becoming aroused and maintaining a full erection for a long time. However, many times he is unable to ejaculate and he finds this very frustrating. Could this “problem” be caused by a medical condition, or could certain medications cause it? Is this more common in older men?

Dear Reader: While this problem can occur in men of any age, it is more likely to occur in an older man. The reasons could be physical or psychological, and since you asked about medications, that, too, could be a contributing factor. If he can masturbate successfully, it might just be that he requires more friction than he gets from intercourse. But rather than guess, my advice is that he consult with a urologist, who would be able to identify any medical problems, and if there aren’t any, then a sex therapist might be able to help him out.

Ask Dr. Ruth appears every Sunday. Write to Ruth Westheimer, King Features Syndicate, 235 E. 45th St., New York, NY 10017 or leave a message at her Web site,