I started experiencing this problem around a year ago (maybe it's not even a problem).
The area at the very tip of my penis, right between the Urethral opening and the Frenulum where the most sensitivity is, started becoming hypersensitive. Randomly without any sexual stimulation and at any time in the day or night, it feels like there is a short circuit happening, it's the only way I can describe it. It's half way between pleasure and pain. Sometimes it happens when I'm just sitting down doing nothing. When it happens when I'm walking, it's very uncomfortable and sends pleasure/pain sensations throughout my penis and there is nothing I can do to stop it. It usually lasts around 30 minutes.
The origin is right in the nerve cluster at the end of the penis. it's happening now as I type actually.

Is there a name for this condition and should I be concerned about it?