Hyperactivity in 6months old kitten

Hey everyone, I have a kitten that is behaving strangely, so I thought I would see if anyone has experienced this kind of problem.  

I adopted Tiki-toes 4months ago, she is a polydactyl kitten, and she is pretty normal for the most part. Tiki is 6months now, and is on a healthy almost grain-free diet, has a good appetite, and has had all her vaccinations.   I noticed early on that when she plays hard she starts panting, and just figured it was normal for a kitten her age, and she would settle down eventually.

The problem is that sometimes she gets over-stimulated, and way too excited, almost like she's ADD or something. This is especially bad if I take her outside on a leashed walk, which she LOVES to do.  She gets herself so worked up (like she's had caffeine) I worry about her having a heart attack! I have had a couple of times when she behaved normally on a walk outside, stayed relaxed, and really enjoyed herself, so now I wonder what is normal? 

I have never had a kitten behave this way, so I am not sure what to try, and I wonder if she has adrenal issues?    Any input or feedback on what could be causing this hyperactivity would be greatly appreciated.

Thanks everyone!

Hello Astettler,

Your kitty is only 4 months old and is still very much a kitten. They are at certain times kind of release all their energy during play by running and climbing. In other words, they are still very active.
It's normal for them to pant after some rigorous excercise or running about. My boy pants when he runs like crazy in the house and after that he'll slow down and rest. It's perfectly normal. Unless you are saying that your kitty pants while doing nothing, then this is a medical issue already.
Active cats are good as they burn off their food and thus don't put on weight.
Is your kitty spayed? If not, get her spayed. Spaying her will do her lots of good.
BTW, she is a lovely sweet looking kitty [emoji]10084[/emoji]️

Thanks for the input, I have had cats all my life, and I know kittens are generally 'frisky', and a bit crazy. I'm just not convinced she's acting normal for her age, think kitten but add caffeine! Or like a small kid on a sugar or caffeine high. Seems to crazy to be normal.