The top of my back has been hurting. I have a hump. Could that be serious? I am 29. I've had the hump in my back for as long as I can remember.

Unlikely but. This pain is most likely muscular due to being off center in terms of your spine's balance with the hump you are describing most likely representing a scoliosis or a kyphosis or "round back" and less likely related to a endocrine or gland problem. You need to be seen by your doctor. Based on the length of time you describe having it it is most likely a spine deformity.
Kyphosis. You may have an elevated kyphosis in your spine for a variety of reasons. I would not hesitate to be seen for an accurate diagnosis and to discuss treatment options.