Nope, not at all... it's most likely a calcium deficiency but without a diary, I don't have enough information to suggest to you WHY you have this going on. Calcium deficiencies come about for a couple of reasons - it can be caused by too much nitrogen which locks out the calcium... it can be caused by a PH level that isn't in the right range, it can be caused by not giving it enough bloom nutes at a particular age.. but I don't even know what you're growing, how old it is, nothing... So please, start a diary and join the community - we WANT to help but we need INFORMATION in order to do so!
Good luck...