Why does my iPhone 5s lose battery so fast?

This started recently. I've had my phone for about 5 months and about a month ago it started losing battery Really fast. I always charge it in the night when I'm sleeping, so it's fully charged in the morning when I go to school. Before, I would have maybe 50% battery left after a school day of 7 hours, but now it's dead before I'm even home. It literally loses 1% every minute while I'm using it. It also gets really, really hot when it's in the charger. So hot that I almost can't hold it. It never did that before unless I was using it while being in the charger. I had 40% an hour ago and I was listening to music on Spotify and after maybe 30 minutes, it was down to 10%. Usually I can go on an 18 hour car drive using Spotify the whole time and STILL have battery left when I reach destination. Earlier today I had 6%, I put it in the charger, it goes to 7% after like 4 minutes and then I ask Siri to write a message for me and while being in the charger, my battery goes down to 5%. How is that possible? I shut all my apps down, bluetooth is off, brightness is not at it's highest, hotspot is turn off. What can I do to fix this?

That's NOT normal, AT ALL, the only way to fix this issue is either replace the battery (or the phone if the phone is defective). Do you have insurance on your phone? If so you can get a free replacement.

ALSO: Did you know there are iPhone 5 and 5s cases that help to boost your battery by 50 to 100%, because the case has RECHARGERABLE BATTERIES INSIDE THE CASE! So everytime you charge your phone, it also recharges the batteries inside the case. There's a "switch" on the case of the phone and all you do is flip the switch and the phone cases starts to charge it! I tested it yesterday, and it wasn't too bad. Results? I had 19% battery. I flipped the switch on, and in 30 minutes my iPhone 5 case charged my iPhone up to 71% then stopped (as the case batteries needed to be recharged again). You can use this everyday, too, and whenever you plug your phone into the wall to charge it, it ALSO recharges the batteries in the case. This means everyday you have 50% to 100% more battery life DAILY! I paid $60 for my case, and it charges 50% extra battery into the phone. There are cases for 100 bucks+ that can charge supposedly anywhere from 100% more battery up to supposedly 200% extra battery (so that's 2 extra full charges + the 1 full charge you already have, so 3 total FULL charges per day, that's crazy).

So yeah, replace your battery and see if that helps. If not, it's your phone. That's NOT normal at all. I have had all the iPhones and losing over 1% per minute means your battery is BAD (or the phone is). I'd also recommend buying a case that can recharge your phone and add an extra 50% to 100% battery without having to carry around your charger and plug it into a wall.

In its warranty, you can send it to the Apple repair store to fix. And do you make sure it has been chargered full of power 100% in the morning? Maybe there's something wrong with the charger. But it is nearly impossible, so you can also replace a new battery for your iPhone by yourself following the iFixit. Before this, you must buy a new replacement battery for your iPhone 5.