Just say it. Your brother might want to hear directly from you that you love him. If the two of you have had a tense relationship in the past, saying "Just so you know, I love you, no matter what" can be a big step in moving your relationship forward.

Write him a letter. If you have a hard time expressing emotions, writing it down in a heartfelt letter or note can be effective. You might say it in a birthday card. You can inject humor by mentioning something from your childhood. For example, you could say something like, "Despite all those times you gave me a wedgie in public, I love you bro."

Tell him in a creative manner. Let your brother know you love him in an unexpected way. Post a picture of the two of you when you were young on a social networking page on National Siblings Day, which is April 10. It could be a funny or slightly embarrassing picture, like him picking him nose, with a caption like "Had to do it bro! Ha-ha, happy National Sibs Day. I love you." You could send him a slideshow of pictures of the two of you growing up, or send him a video message from your family expressing love to him on his birthday.

Show him you love him through your actions. Actions speak louder than words. Show up for his big events, whether it's his wedding or his first marathon. Surprise him by flying across the country to celebrate a birthday with him. If you can't be with him during his special moments, send a care package with items related to the event so he knows you care.