A lack of affection from one partner can put a real strain on a relationship, as the other person may feel unloved, unwanted or lonely. If your girlfriend isn't showing affection to you, there are a number of factors that could be to blame. Bear in mind that people have different ways of expressing affection, and these can vary between men and women. It doesn't have to be all hearts and flowers for someone to care for you deeply.

People have preferences for the way they give and receive affection, according to Dr. Gary Chapman, author of "The Five Love Languages: The Secret to Love That Lasts." He lists quality time, words of affirmation, gifts, acts of service and physical touch as different modes of expressing love. Look at all these areas to identify how your girlfriend is communicating affection that you may have missed. If she doesn't kiss you or whisper sweet nothings, does she cook, buy you underwear, or watch the ball game with you?

Women also express their affection in terms of what they don't do, more so than men. Females show love and affection for their partners by being less assertive and less dominant, according to a University of Texas in Austin study written about in "Love Knows No Gender Difference" by Barbara Bronson Gray, published in Personality and Social Psychology Bulletin. The news may stun men, who generally show affection by initiating sex, sharing chores, or doing joint leisure activities. If your girlfriend allows you to be more dominant in the relationship, that could mean she's being affectionate.

If you can not spot any signs of affection, the next step is to talk. Approach the subject when there are no other distractions, and begin the conversation without blaming your partner, the National Healthy Marriage Resource Center advises in "A Game Plan for Effective Communication." Describe the issue in terms of how it feels for you, with a specific example to make your point. A good statement might be: "I am feeling a distance between us at the moment. I think it's been a month since you last hugged me." Listen carefully to her response.

If your girlfriend opens up about what precisely is causing her to be cold, this is your chance to fix it. If she doesn't identify a problem you can solve, then tell her what you want to happen, so that the situation improves. Be positive and specific, saying something like: "I love you, and I need to be able to hold you. Would it be OK to have a daily cuddle after dinner?" Asking to get your needs met isn't a guaranteed solution, but opens the channels of communication. Being honest with your partner can only benefit the relationship.