Love is a powerful motivation that alters how you act and think. The physical feelings that are related to love usually happen without you having to think about them, and are often beyond your conscious or willful control. People in love act like addicts and experience some of the same physical reactions, says researcher Helen Fisher, who holds a doctorate in anthropology. You are more likely to display intense happiness when you are with the person you admire, and you are more likely to be anxious to see them again, even after a short separation and you may become stressed at the thought of losing the one you love.

Intense Happiness

When in love, you are likely to feel intense joy and happiness. You may find that you are usually in high spirits and a generally good mood. It would probably take something really serious to get you down. You are at your peak in the presence of your romantic partner. You smile and laugh more, so much so, that you feel light-headed at times.

A Pounding Heart

The very thought of being around the object of your affection can make your heart beat faster than normal. The bursts of extra energy that accompany love, and which causes you to be more physically and emotionally active, also play a part in making your heart beat faster.

Profuse Sweating

The agitation and anxiety that comes with being in love can cause you to sweat more than usual. You may feel this all over your body or in particular areas such as in the palm of the hands.

Changes in Appetite

Being in love can result in changes in eating habits. You may eat less often. At other times, you may have no desire for food at all, even if the food presented is one of your favorite foods.

Energetic and Active

When you are in love, you may feel as if you have a limitless supply of energy. You may become more active, finding it hard to keep still or focus fully on anything not related to the one you love. You may also become more impulsive, doing things on a whim or at the spur of the moment -- especially if it involves your romantic partner.

Tired and Exhausted

The huge amounts of energy that you expend in thinking about and interacting with the person you love can be draining. You may begin to feel more and more exhausted. It may also be difficult to sleep, which can also contribute to the fatigue.

Love Hurts

Love can cause you to feel physical pain. The fear of getting hurt or losing a romantic partner can affect different areas of your body in the same way that stress does. This can result in such issues as back pains, headaches and stomach cramps.