The hypothalamus is the part of the brain that controls hunger and thirst. It is a small part of the forebrain that regulates many bodily functions, including body temperature, heart rate, sleep patterns, and the release of hormones from many glands, especially the pituitary gland. The hypothalamus performs many of its "body balancing" jobs either by directly influencing the autonomic nervous system or by managing hormones.

Hypothalamic dysfunction can occur as a result of diseases, including genetic causes, infection or inflammation, and injury as a result of trauma, surgery, or radiation. Symptoms of hypothalamic disease can have many different symptoms, depending on the cause. The most common symptoms include increased appetite and rapid weight gain, extreme thirst and frequent urination (diabetes insipidus), low body temperature, and slow heart rate.