My little Cassie

So my mom and I took our oldest cat to the vet tonight to see what's wrong with her. The nice kitty doctor said that it was something with her thyroid gland that will affect her whole body. That includes lungs, heart, liver, pancreas, etc. The vet said that she needs to do blood work. So, extremely reluctantly, we decided it was best to leave her there over night. I'm not gonna lie, it killed me to leave her there. I cried. Even though I know that she will be perfectly safe and fine. This is the first night that she hasn't been home. With me. We'll get her back tomorrow and the results will be in Thursday or Friday. Cassie is 16 years old, which is very old for a cat. I'm very nervous that when the results come back, they won't be so good. My little girl is, of course, in my prayers.