The butterfly-shaped gland in your throat pumps out a hormone that regulates your metabolism and body temperature. If it’s producing too little , metabolic changes can cause your subcutaneous ( underneath the skin) tissues to get bigger. “Everything fills out a little,” says Stewart. “The effect is often described as looking a bit like a toad.” You’ll probably also feel chilly and weak, and may notice that you have dry skin or that your periods have become irregular. Your doctor can run a simple blood test and prescribe medication if necessary.