Feeling a knot in your stomach when you think about your boyfriend can be a sign of excitement, anxiety or fear. Though it is normal to have "butterflies" when thinking about someone that you like, if the knot in your stomach causes you distress, it may be about something more serious.

Excited and Nervous

If you and your boyfriend have not been dating very long, it could be that you still have those initial feelings of excitement and nervousness about seeing him. Perhaps you feel anxious about making a good impression or can't wait to put your arms around him again. Your body is responding in a primitive way to your thoughts -- by releasing hormones that cause the feeling of a knot in your stomach, says psychologist Elvira G. Aletta in the "Psych Central" article "10 Ways to Lower Anxiety." It isn't that there is anything wrong, but rather that things are very right.

Fear of Rejection

A knot if your stomach could also indicate fears that you have about the relationship. For example, if you have thoughts such as, "He must be thinking about breaking up with me," or "Why hasn't he called me back?" you are engaging in unhelpful thinking that is causing your anxiety. Guessing at his thoughts, trying to read his mind, jumping to conclusions or trying to predict the future with "What if?" questions will all cause that knot in your stomach, says psychologist Susan Heitler in the "Psychology Today" article "Worrying in Relationships: Three Habits That Invite Anxiety." Try to gain control of your runaway anxious thoughts.

Bothersome Issues

Perhaps there is an actual problem with your boyfriend that is causing you to feel uneasy or afraid. If your boyfriend is overly controlling, to the point that you can't spend time with your friends anymore, that might be a cause. If he is needy or clingy and won't give you enough space, that could be another trigger. Identify what is causing your fear or anxiety so that you can start to solve the problem, as suggested in the University of Florida Counseling and Wellness Center article "How to Handle Fears."

Missing Him

A knot in your stomach when you think about your boyfriend could mean something as simple as you miss him. If you haven't seen him in a while, or the two of you have been going through a difficult time, it could be that you are feeling the effects of being apart.