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
- maintaining daily physiological cycles
- controlling appetite
- managing sexual behavior
- regulating emotional responses
- regulating body temperature
Use this interactive 3-D diagram to explore the hypothalamus.
The hypothalamus has three main regions. Each one contains different nuclei. Nuclei are clusters of neurons that perform vital functions.
The anterior region is also called the supraoptic region. Its major nuclei include the supraoptic nucleus and paraventricular nucleus. 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.
The anterior region of the hypothalamus also helps regulate body temperature through sweat.
It also maintains circadian rhythms, which 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. Learn more about the circadian rhythm and sleep.
The middle region is also called the tuberal region. Its major nuclei are the arcuate nucleus and ventromedial nucleus. Part of the paraventricular nucleus is also located here.
The arcuate nucleus is involved in appetite and releasing growth hormone-releasing hormone (GHRH). The ventromedial nucleus also helps regulate appetite and growth.
The posterior region is also called the mammillary region. The posterior hypothalamic nucleus and mammillary nucleus are its main nuclei.
The posterior hypothalamic nucleus helps regulate body temperature by causing shivering and blocking sweat production.
The mammillary nucleus is involved in memory function.
Some of the most important hormones produced in the anterior region of the hypothalamus 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.
- Gonadotropin-releasing hormone (GnRH). Production of GnRH causes the pituitary gland to produce important reproductive hormones, such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
- Thyrotropin-releasing hormone (TRH). Production of TRH 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 muscles, heart, and gastrointestinal tract.
- Somatostatin. Somatostatin works to stop the pituitary gland from releasing certain hormones, including growth hormones and TSH.
- 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. Learn more about oxytocin.
- Vasopressin. Also called antidiuretic hormone (ADH), vasopressin regulates water levels in the body. When vasopressin is released, it signals the kidneys to absorb water.
In the middle region of the hypothalamus, GHRH stimulates the pituitary gland to produce growth hormone. This is responsible for the growth and development of the body.
When the hypothalamus does not work properly, it’s called hypothalamic dysfunction.
Hypothalamic dysfunction plays a role in many conditions, including:
- Diabetes insipidus. If the hypothalamus does not produce and release enough vasopressin, the kidneys can remove too much water. This causes increased urination and thirst. Learn more about diabetes insipidus, which is unrelated to diabetes mellitus.
- Prader-Willi syndrome. This is a rare, inherited disorder that 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 occurs when the pituitary gland does not 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.
- Gigantism. Gigantism occurs when the pituitary gland produces too much growth hormone. It typically affects children and adolescents. The primary symptom is a tall stature, but it can also result in symptoms such as a head that’s larger than expected or large hands and feet. A pituitary tumor is the most common cause of gigantism and acromegaly, a similar condition. Hypothalamus abnormalities can also cause these conditions by stimulating the pituitary gland to produce too much growth hormone.
- Acromegaly. Acromegaly is also caused by the pituitary gland producing excess growth hormone. It’s similar to gigantism, except it typically affects adults. Because the growth plates have fused by adulthood, acromegaly does not affect a person’s height. It can result in symptoms such as large hands and feet or enlarged facial features (like the nose, lips, or tongue).
Symptoms of hypothalamus disorders
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 problem with the hypothalamus include:
- unusually high or low blood pressure
- fluctuations in body temperature
- unexplained weight gain or weight loss
- increased or decreased appetite
- short stature
- delayed onset of puberty
- frequent urination
Causes and risk factors
Several things can cause hypothalamic dysfunction, including:
- head injuries
- surgery involving the brain
- autoimmune conditions
- certain genetic conditions, such as growth hormone deficiency
- congenital irregularities involving the brain or hypothalamus
- tumors in or around the hypothalamus
- eating disorders, such as anorexia or bulimia
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.
To reduce your risk of a hypothalamus condition, make sure you’re aware of how much fat and sugar you consume per day.
Get enough sleep
A 2014 study in rats found that sleep deprivation was associated with hypothalamic dysfunction. In addition, researchers suggested that sleep deprivation may increase someone’s risk of neurological disease.
If you have a hard time sleeping, consider trying natural remedies to help you sleep and keep your hypothalamus working properly.
Like eating a balanced diet and getting enough sleep, regular exercise boosts your overall health.
A 2016 study looked at three groups of obese mice over a 12-week period:
- mice that were given a high fat diet and a voluntary running wheel
- mice that were given a high fat diet and no voluntary running wheel
- mice that were given a normal diet and no voluntary running wheel
The mice that were given a voluntary running wheel experienced less weight gain than the mice who ate a high fat diet but did not exercise.
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.