Parasites? Inside of me? Ruining my sleep?

One of the things that my clients are very often surprised about, is when I tell them that we are going to do lab testing for parasites. Very often I hear, "What do you mean, parasites? I'm a healthy person. I'm a clean person. I wash every day!"  The thing is, you can get parasites through uncooked meat, through kissing someone, using different swimming pools etc....