No they are not.
People who have Bipolar disorder have SEVERE mood swings that cause deep depression and extreme mania.
I really wish people would do some research on this disease before commenting on it.
Did you mean to say mood swings ARE normal, but that people who identified with BP have abnormal mood swings or are you saying all mood swings are abnormal?
Mood swings are a normal part of life, they have been from the beginning of time.