Don't think I ever talked about it in more detail here, but I was recently diagnosed with asthma.
It took me ca 6 years after developing asthma to figure this out thanks to the doc I went to 3 years ago with breathing problems when doing sports. They only had my heart rate and blood pressure tested (good idea because my dad has high bloodpressure, bad idea because I specifically mentioned breathint issues).
She was sure that more running would help me and my apparently slightly low blood pressure, while ignoring how weird it was that it took me really long to regain normal breathing after the exercise.
The thing is: I was in a professional childrens' choir for several years, breath Training, vocal Training, all of that, and only after figuring out that asthma would ecxplain a lot and starting the journey to get tested did I realize a few things as being kinda weird.
I started in that choir when I was 10, and got sorted into second alto, the lowest female voice. That was all good and dandy. At ca 13 I got really into a musical telenovela show and since most of the women in it were sopranos I tried singing high to copy them.
I remember that going terribly for a while until it stopped being difficult and I instead started having issues with some of the lower notes, not the lowest mind you, but the lower middle range of alto voices.
Turned into the Mini weapon of the voice for parts where we had to sing high because it wasn't a problem for me, but going back down to low notes was really difficult after a singing an e5, and not just the normal difficulties of vocal changes.
I asked the conductor to retest me a few times because I was sure I could be a first soprano, but they didn't want to, both because 2nd alto was a small voice and because I was clearly capable of being one and people's voices usually don't change that much.
Over the years I just got better and better at controlling my voice and my breathing, my vocals ranging from e3 to f5, if not wider, but all depending on the day.
During Winter I would drink a lot before singing to pre-wet my throat and vocal chords because drinking cold water always made me have to retune my voice and continually check it because it would be changing for a few minutes, making my voice control better and fixing an issue that others never had to deal with in the first place.
When I swapped choirs after 8 years to go to uni, I auditioned on a cold day, right after biking there in 0°C/32°F. I could literally not produce low notes at all because I didn't have time to warm up (whoops me for being late lol) and did actually get put in 1st Soprano.
Now 3 Semesters later I was finally diagnosed with Asthma and got an inhaler that is doing wonders for me when I have to go out in the cold or want to do sports. The thing is that I can't reach high notes easily anymore when I do use the inhaler.
Part of my ability to sing so high was probably related to the fact that my throat would close up and thus allow me to produce higher notes in the first place.
My range is still really big and it's funny to think that combining my vocal Training from choir, my vocal Training for speaking more masc as a nonbinary person and wheather I use my inhaler or not, allows me to record a wide variety of songs.
I am now back to singing 2nd alto in this new choir, don't have to check my Sound constantly just because I drank a sip of water and my singing has generally become more relaxed.
If you're a singer and your vocal range suddenly changed or you have a similar experience with repitching/checking your voice after drinking water, maybe talk to someone to see if you can get tested for asthma too.