You know the feeling because you’ve experienced it — a nagging tendency to collect facts and see where they don’t line up, to casually question your spouse to see if dates and times are consistent. You make your heart race with the many scenarios you run through in your own mind, wondering whom they are bedding and how you could be such a sucker.

Or you’ve watched your otherwise reasonably sane spouse morph into this green-eyed monster, voice raised, eyes bulging, accusing you of staring, hiding, flirting and scheming.

In couples therapy, at times, I find it hard to figure out who is more tortured: The jealous ones whose detective skills are so time-consuming and petty, or the “jealousees,” who may revert to lying to keep the peace, hurt that they are constantly having to defend themselves and offer explanations for every longer-than-average trip to the bathroom.

There are different shades of jealousy, from the sort that hides behind the guise of being protective and loving (as psychologist Havelock Ellis described it: The “dragon that slays love under the pretense of keeping it alive”), to the militant kind that is a cornerstone for abusive relationships, alienating the spouse from friends and even family.

Often the jealous ones will give the excuse that they have experienced deceit in the past, as if that gives them license to torture their trustworthy present mates. The hardest part is breaking the “snooping cycle”: the modern technology of texting, e-mailing, and Facebook have made snooping a full-time job. This ain’t just about lipstick on the collar; we are talking about “sexting,” “chatting,” and “friending.”

A study done in 2009 found that the “cuddle hormone” oxytocin, which makes us more likely to trust others, find them attractive, and remember their faces, may also amplify the feeling of envy and gloating.

When all is said and done, if your partner IS trustworthy and you’ve heard about your “jealousy problem” in other relationships, it might be time to work on this ugly side of yourself. First step, of course, is admitting it, because denial and justification are two common dynamics Ms./Mr. Jealous uses. Here are some clinical and therapeutic things to ask yourself:

— Trust and jealousy are obviously related, so were you able to trust your parents to do what they promised? Was attention evenly divided among children or did you often feel shorted?

— If you were cheated on in the past, and are therefore hypervigilant and jealous, have you tried talking to your partner about the specific things they do that remind you of that last relationship?

— Does your jealousy spread to other people? That is to say, are you envious of your coworkers or friends, are you greedy?

— Have you been told your jealousy is out of normal range, that you are paranoid and suspicious? Do you feel as if you get fixated on situations, that your obsessions are beyond your control?

Doctor's orders? Keep reading:

1. Think about how it takes courage to trust. Acknowledge that letting yourself “fall” in love is about hoping that you’ll be metaphorically caught. Yes, it feels scary, but if you can back off from trying to control all aspects of it, it will be more fun.

2. Of course you have “abandonment issues,” most people do. It’s not that novel or special, and it’s not an excuse to drive your significant other crazy. Talk, think, and write about them, heal, and move on. You’re a grown-up now, and you don’t want to poison your adult relationship with those issues from decades ago.

3. Often jealousy is a reaction to your own (sometimes even unconscious) desire for others. We are sexual beings, and as long as you don’t lie, cheat, and break trust running after that object of your desire, you are OK. Acknowledge your desires and you’ll stop thinking it’s your spouse who has a wandering eye.

You can’t own anyone and you can’t “lose” them if they don’t want to go, so if insecurity is making you a monster, you are the only one who can really tame it.

Dr. Belisa Vranich is a psychologist and sex expert. She is the author of three books, including her latest "He's Got Potential," which is in stores now. Do you have a "Dear Doc" question? E-mail Dr. Vranich at DrBelisa@gmail.com and check out her Web site at www.drbelisa.com.