Am I experiencing bipolar symptoms?

I was diagnosed with ADHD when I was 5 (I'm now 27). Over the past 7 or 8 years,I've been having mood swings that last for a period of time.I've noticed over the past couple of years,they've been increasing in intensity.

I have periods where I'm super hyper and happy and super confident to where I talk a lot and am way more social than normal and my self esteem skyrockets.I'm talking a TON of energy and over happiness.Almost like I've consumed a bunch of caffeine.The good thing is I can get my work done a lot faster than normal.And my thoughts race and I feel like I'm moving at lightning speed. It's crazy. Honestly I wish I could be like this all of the time. People like me more,I'm more social, and make more friends when I'm like this.During those times, I have a hard time sleeping too.

And then I'll have periods where I'm totally antisocial, and feel extremely depressed and emotional and have feelings of hopelessness.And during those times, my self esteem is so low and I'm socially awkward.And I end up either feeling nothing at all or irritable. I literally feel like I'm the lowest piece of crap in the world.And all I want to do is sleep. Sometimes it gets so bad that I end up calling out of work or skip class because I can't stand the thought of being social.And that is not normal for me. :/

And sometimes I'll feel completely normal.Like nothing is wrong at all. It's so weird.

Is it possible for someone who has been diagnosed with ADHD to end up having bipolar as well?

Should I make an appointment with a psychiatrist? Or am I just overreacting?

I would make an appointment with a psychiatrist. These do sound like bipolar symptoms, but I can't diagnose you. It is possible that your ADHD is in conjunction with bipolar, it is also possible that your ADHD was misdiagnosed and is part of bipolar disorder. Again, something to talk to a doctor about.

Personally, I noticed something in third grade (about 8 years old), but wasn't diagnosed until 21. In high school my symptoms became very apparent. I mostly struggled with depression. Having bipolar II, I only have hypomanic episodes, much like what you experience, and didn't see them as something negative.

A few other signs
Reckless behavior - spending sprees, increased sex drive, gambling, risk taking, ect.
Irritability - especially at small things. People may think you over react
Thoughts of feeling worthless, or a failure.
Thoughts of suicide or death (Please go to the ER, call 911, or call a crisis line)
Lack of interest in things you enjoy

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