Welcome Sanada. Yes there can be some subtle and some not so subtle symptoms. I would suggest reading some literature on BP There's an easy to read booklet on this website; it can be downloaded for free (it's located on the left hand side of the site): http://www.mooddisorderscanada.ca/

Lotus is correct the first step is to speak to your GP. During this appointment request a full physical including blood work. There are medical issues that can mimic BP symptoms. If the physical doesn't show anything I would suggest asking for a referral to a Psychiatrist. As far as being locked up in the hospital and forgotten about that isn't going to happen. If it's bipolar it's can be treated and if a hospital stay is necessary it's highly unlikely that it would be long term.

While waiting for an appointment with a Psychiatrist I would suggest starting to track your moods. I use this one online:

http://www.medhelp.org/land/mood-tracker