What Is the Hypothalamus?

Woman with picture of brain
Getty images/RubberballCLOSED

The hypothalamus controls the interaction between your endocrine or hormone producing system and certain parts of your nervous system.

Where is it located?

If you drew a line from the middle of your eyebrows directly back to the center of your brain you would locate a pea-sized structure called the hypothalamus. What this part of the brain lacks in size it makes up for in function.

What Does it Do?

Think of the hypothalamus as the "smart home control system" of your body.

Its primary responsibility is to keep your body functions well balanced and stable. The hypothalamus controls and coordinates much of the body’s involuntary functions like temperature regulation, hunger, thirst, sleep, and mood. By acting in response to inputs from the brain and from hormones the hypothalamus adjust the body’s internal balance, or homeostasis.

Another important function of the hypothalamus is to regulate the pituitary gland . The hypothalamus produces substances called releasing hormones that activate the pituitary gland to stimulate other hormone producing parts of your body like the thyroid and the ovary. By controlling the release of these hormones the hypothalamus is also directly involved with your metabolism, growth, sex drive, and of course your menstrual cycle.

That's right, your period really is all in your head! Well, at least the control of it is.

Menstrual Cycle Control 

Your hypothalamus produces a hormone called GnRH or gonadotropin releasing hormone.

Under normal conditions, your body releases GnRH in a pulsatile fashion. This intermittent release causes the pituitary gland to coordinate the release of  two other hormones called FSH or follicle stimulating hormone and LH or luteinizing hormone. FSH, in turn, stimulates the ovary to produce estrogen and LH stimulates the ovary to produce progesterone.

The cyclic changes of these hormones are responsible for your menstrual cycle which includes both ovulation and if no conception or pregnancy occurs your menstruation or period. 

When Things Go Wrong

Since the hypothalamus is the control panel of your menstrual cycle, certain conditions that disrupt the body's balance and interfere with the healthy functioning of the hypothalamus can also interfere with your menstrual cycle. When the release of GnRH does not happen in the normal pulsatile fashion FSH and LH are not properly produced by the pituitary gland. Without stimulation from these hormones, the ovaries do not produce FSH and LH and ovulation does not occur. Without ovulation, there is no menstruation. This type of a missed period is called hypothalamic amenorrhea.

Common causes of hypothalamic amenorrhea include psychologic stress, physiologic stress from a chronic disease or excessive exercise or excessive weight loss. That's right your period or lack of it can be  a sign of an underlying problem or other imbalance in your body.

As always, if you are experiencing any problems with your menstrual cycle please discuss it with your healthcare provider.

Updated by Andrea Chisholm M.D.

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