What is the hypothalamus?
The hypothalamus is a small region of the brain. It’s located at the base of the brain, near the pituitary gland.
While it’s very small, the hypothalamus plays a crucial role in many important functions, including:
- releasing hormones
- regulating body temperature
- maintaining daily physiological cycles
- controlling appetite
- managing of sexual behavior
- regulating emotional responses
Anatomy and function
The hypothalamus has three main regions. Each one contains different nuclei. These are clusters of neurons that perform vital functions, such as releasing hormones.
This area is also called the supraoptic region. Its major nuclei include the supraoptic and paraventricular nuclei. There are several other smaller nuclei in the anterior region as well.
The nuclei in the anterior region are largely involved in the secretion of various hormones. Many of these hormones interact with the nearby pituitary gland to produce additional hormones.
Some of the most important hormones produced in the anterior region include:
- Corticotropin-releasing hormone (CRH). CRH is involved in the body’s response to both physical and emotional stress. It signals the pituitary gland to produce a hormone called adrenocorticotropic hormone (ACTH). ACTH triggers the production of cortisol, an important stress hormone.
- Thyrotropin-releasing hormone (TRH). TRH production stimulates the pituitary gland to produce thyroid-stimulating hormone (TSH). TSH plays an important role in the function of many body parts, such as the heart, gastrointestinal tract, and muscles.
- Gonadotropin-releasing hormone (GnRH). GnRH production causes the pituitary gland to produce important reproductive hormones, such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
- Oxytocin. This hormone controls many important behaviors and emotions, such as sexual arousal, trust, recognition, and maternal behavior. It’s also involved in some functions of the reproductive system, such as childbirth and lactation.
- Vasopressin. Also called antidiuretic hormone (ADH), this hormone regulates water levels in the body. When vasopressin is released, it signals the kidneys to absorb water.
- Somatostatin. Somatostatin works to stop the pituitary gland from releasing certain hormones, including growth hormones and thyroid-stimulating hormones.
The anterior region of the hypothalamus also helps regulate body temperature through sweat. It also maintains circadian rhythms. These are physical and behavioral changes that occur on a daily cycle. For example, being awake during the day and sleeping at nighttime is a circadian rhythm related to the presence or absence of light.
This area is also called the tuberal region. Its major nuclei are the ventromedial and arcuate nuclei.
The ventromedial nucleus helps control appetite, while the arcuate nucleus is involved in releasing growth hormone-releasing hormone (GHRH). GHRH stimulates the pituitary gland to produce growth hormone. This is responsible for the growth and development of the body.
This area is also called the mammillary region. The posterior hypothalamic nucleus and mammillary nuclei are its main nuclei.
The posterior hypothalamic nucleus helps regulate body temperature by causing shivering and blocking sweat production.
The role of the mammillary nuclei is less clear. Doctors believe it’s involved in memory function.
Use this interactive 3-D diagram to explore the hypothalamus.
When the hypothalamus doesn’t work properly, it’s called hypothalamic dysfunction.
Several things can cause hypothalamic dysfunction, including:
- head injuries
- certain genetic disorders, such as growth hormone deficiency
- birth defects involving the brain or hypothalamus
- tumors in or around the hypothalamus
- eating disorders, such as anorexia or bulimia
- autoimmune conditions
- surgery involving the brain
Hypothalamic dysfunction plays a role in many conditions, including:
- Diabetes insipidus. If the hypothalamus doesn’t produce and release enough vasopressin, the kidneys can remove too much water. This causes increased urination and thirst. Unlike people with diabetes mellitus, people with diabetes insipidus have stable blood sugar levels.
- Prader-Willi syndrome. This is a rare, inherited disorder. It causes the hypothalamus to not register when someone is full after eating. People with Prader-Willi syndrome have a constant urge to eat, increasing their risk of obesity. Additional symptoms include a slower metabolism and decreased muscle.
- Hypopituitarism. This disorder happens when the pituitary gland doesn’t produce enough hormones. While it’s usually caused by damage to the pituitary gland, hypothalamic dysfunction can also cause it. Many hormones produced by the hypothalamus directly affect those produced by the pituitary gland.
Symptoms of hypothalamic conditions
Hypothalamic conditions can cause a range of symptoms. Which symptoms you may experience depend on the part of the hypothalamus and types of hormones involved.
Some symptoms that could signal a hypothalamus problem include:
- unusually high or low blood pressure
- body temperature fluctuations
- unexplained weight gain or loss
- changes in appetite
- short stature
- delayed onset of puberty
- frequent urination
Tips for a healthy hypothalamus
While some hypothalamus conditions are unavoidable, there are a few things you can do to keep your hypothalamus healthy.
Eat a balanced diet
While eating a balanced diet is important for every body part, it’s especially crucial when it comes to the hypothalamus. A recent study in mice found that eating a high-fat diet led to inflammation of the hypothalamus.
Another study in mice found that a high-sugar diet also caused inflammation of the hypothalamus. To reduce your risk, make sure you’re aware of how much sugar you consume per day.
Get enough sleep
A 2014 study found that sleep deprivation was associated with hypothalamic dysfunction in rats. In addition, researchers involved in the study suggest that sleep deprivation may increase someone’s risk of neurological diseases.
Like eating a balanced diet and getting enough sleep, regular exercise boosts your overall health. However, if you’re having trouble with the diet part, exercise is particularly important. A 2012 study involving mice found that even a mild amount of regular exercise reduced hypothalamic inflammation related to a high-fat diet. Not sure where to start? Check out our beginner’s guide to working out.