I'm 23, suffering with a number of strange symptoms which so far nobody has been able to figure out.
Sometimes my blood pressure, pulse and temperature are completely fine, then sometimes they dip. This happens frequently every other day pretty much. I just took my readings: blood pressure 112/70, pulse 53 BPM, oral temperature of 35.5 degrees celsius/95.9 degrees farenheit (been as low as 35.1 C/95.18 F and I got 34.8 C/94.64 F once but might have measured that one wrong). I am not fit, I struggle to even complete a half mile run even though I work out casually.
I feel breathless at times (not reaaally bad gasping for breath type breathlessness but I feel like a stuffy, suffocating feeling in my chest and feel like I can't get a full breath), get pins and needles and I can come over faint where I have to get on my knees and put my head to the ground as though I'm praying, then the symptoms gradually subside. Sometimes when I get a big adrenaline dump (e.g. watching sports) I can hear and feel a sound very similar to a bubble bursting which is synchronized to my heartbeat. This sound occurs in my upper chest to lower neck area I think. I can't remember exactly where it is located because it has only happened a few times now (I don't get worked up very often), but it sounds exactly like bubbles bursting.
On a 24 hour ECG my pulse dropped low at times, especially during the night, and raced at other times (maybe the racing was from being active though, as I went for a gentle jog in case something went wrong under stress) and I had skipped heartbeats here and there but they were not concerned about anything.
When I go to the docs they just take my vitals and say they're fine (because sometimes they are) they don't take it seriously when I tell them that sometimes my vital signs drop all they care about is what the readings say there and then... Or sometimes if something is off they say my pulse is a bit alarmingly low and send me for cheap tests like ECGs (or standard full blood count blood test) then say it was fine and forget they ever saw my pulse in the 40s and poor BP etc. then they just send me home and the illness continues.