Cat mysteriously losing weight....

Hello. My name is Amanda...and I currently have two beautiful cats. A long haired calico named Ginger. And a medium haired domestic black and white boy named Remy.
For the past 3 months....Remy has lost weight. He has gone from 8.5 to 7.4 pounds. He has always had a problem with sneezing,runny nose on and off...and one eye that is sometimes a tiny bit swollen then the other. I.always thought maybe he has allergies. I have told my vet about this but he has seen nothing wrong with it at all.

He is eating. He isnt having any diarrhea. I want to say he is peeing slighrly more then usual...but i work all the time..so i cant exactly keep an eye on him. And when he drinks water...he is literally at the bowl for a good 2 to 3 whole minutes. He does sleep though.. A LOT. More then a cat normally sleeps. And he has been attached to me at the hip more then usual.

I have had him into the vets for a checkuo and to check his thyroid. All was fine there. Gave him dewormer...and some hair ball treatment..and changed his diet, cause the food he was on...he would normally throw it right back up after eating it. Since the change..he hasnt thrown up but once. So its an improvement. I will be getting blood work done on him soon as well to see if anything is going on there.

I am fearing that this could be either renal disease...or somethong worse. I just lost a cat back on July to thyroid disease. And I am just petrified that i am seeing my boy go don the same path.....

Any advice?? I could really use some guidance....

My kitty Scooter had lost quite a bit of weight. He's probably 14 or 15 years old. The vet did the blood test and he had a couple of things going on. One was elevated thyroid and the test showed that his kidney function was okay, but not at 100%. She felt it was age related.  Of course the elevated thyroid can increase thirst and they can eat everything in sight. My cat is more vocal. He didn't tolerate the thyroid medication very well though or it was the antibiotic for a different issue. He's on the mend and now I have to consider the thyroid medication again.

Kidney issues and diabetes can also show the same sort of symptoms. The blood test will definitely show what's going on and will show if there is hyperthyroid too.

if he is peeing more... it could be a UTI... but also weight loss and peeing a lot could have something to do with his kidneys... id have your vet run a full check up