What Is The Treatment For Para Thyroid Disease?

I have para Throid disease. The doc did an ultrasound in his office. He could not find any of the 4 glands. He said probably because they are all affected. He needs to keep 1/2 of one in. Will it be easy to find them all once he goes insdie? What are the chances that my voice will change? And how bad will the scare be on my neck? Also, I understand that once they are removed...as will be well. What can you tell me about this disease?Thanks in advance.