The document discusses medical suffixes and their meanings. The suffix "-dipsia" means thirst, and when combined with the prefix "poly-" means excessive thirst or polydipsia. Polydipsia is commonly found in patients with diabetes and is caused by changes in extracellular fluids. The suffix "-crine" means to secrete, and when combined with the prefix "endo-" refers to endocrine glands that secrete hormones internally, such as the pituitary, thyroid, and adrenal glands, into the circulatory bloodstream.