This article covers what the hypothalamus is, what it does, what can affect it, and how to care for it.

The hypothalamus is a part of the brain that contributes to particular roles that are necessary for bodily function.
It is relatively small. T
he hypothalamus is only around the size of a pea, and it contributes less than 1% of the brain’s weight. However, this small brain structure has an impact on almost every system in the body.
The hypothalamus is a part of the larger limbic system, which is a section of the brain that includes the hippocampus, amygdala, thalamus, amygdala, and cingulate gyrus. This system contributes to processes such as emotional and behavioral responses, memory, smell, and the acquisition of new skills.
It sits between the thalamus and pituitary gland on the underside of the brain. It is attached to the pituitary gland by a stalk of tissue. Through this connection, the hypothalamus sends messages to the pituitary gland.
The hypothalamus has many functions that contribute to the overall maintenance of homeostasis in the body.
Homeostasis
Homeostasis is a key responsibility of the hypothalamus, as homeostasis is fundamental to human life.
Homeostasis refers to the self-regulated stable, constant state of the body. It means that a person can maintain consistent internal conditions that allow bodily function, survival, and action. These conditions include the maintenance of body temperature, salt levels, water concentration, blood gasses, respiration, and more.
The hypothalamus works to maintain homeostasis by controlling processes such as:
- stress response
- body temperature regulation
- blood pressure maintenance
- fluid and electrolyte balance
- reproduction
- sexual behavior
- sensitization and desensitization
- emotional response and expression
- growth
- bodily rhythms, such as the nighttime release of melatonin for sleep and other routine fluctuations of hormones
- hormone secretion
- movement
- metabolism, including the regulation of food intake, energy expenditure, energy balance, body weight, appetite, and satiety
The hypothalamus and the endocrine system
Some of these important hypothalamic functions represent the regulation, production, and inhibition of hormones. In turn, these functions also control many other important bodily processes.
The hypothalamus does this by coordinating the endocrine system, which is a network of glands and organs that uses hormones to control certain bodily functions and reactions. These functions and reactions can include the control of processes such as growth, reproduction, and fluid balance.
There are additional functions of the hypothalamus that do not represent endocrine or hormonal function. Clinicians may refer to these as non-endocrine functions. They include temperature regulation, appetite control, and nervous system regulation.
Learn more about the endocrine system, including related disorders, here.
Several conditions and changes can affect the hypothalamus and hypothalamic health. The following conditions can all affect how the hypothalamus functions:
- traumatic brain injury
- brain tumors or metastatic cancer to the brain
- infections
- surgery
- radiation therapy and chemotherapy
- rapid and extreme weight changes
- nutritional deficiencies, sometimes as a result of other conditions, such as anorexia nervosa
- genetic disorders
- hormone disorders
- pituitary deficiency, also known as hypopituitarism
- diabetes insipidus
- paraneoplastic syndromes as a reaction to cancer
- inflammatory conditions, such as multiple sclerosis
Because the hypothalamus controls so many different systems and processes in the body, symptoms of hypothalamic conditions can also vary widely.
For instance, problems with the hypothalamus can range from growth disorders to not being able to regulate body temperature to sleep disruptions.
The exact symptoms will depend on the part of the hypothalamus affected and the body organ or system involved.
The ranging functions of the hypothalamus also make it difficult to pinpoint exact signs and symptoms of hypothalamic dysfunction.
In general, however, signs and symptoms of some hypothalamic conditions can include:
- problems with body temperature regulation, such as always feeling cold or hot
- growth problems
- difficulty maintaining body weight
- appetite changes
- sleeping difficulties
- anxiety and depression
- delayed puberty
- disruptions to the menstrual cycle
Because problems with the hypothalamus can have such a wide range of symptoms, it can be difficult to determine exactly when to contact a doctor — especially if they are symptoms that have occurred for a long period of time.
However, in general, you should always contact a doctor for any changes to your health or new symptoms that arise. This should be the case even if they seem “mild” or not problematic.
Even minor symptoms or changes to your health could indicate that something broader is going on. It is a good idea to keep a log of your symptoms, along with what makes the symptoms better or worse, so that you can give your doctor a full picture of what is happening.
Because the hypothalamus affects so many bodily processes, systems, and organs, the best ways to support hypothalamic health can vary. In general, however, you can do so by:
- supporting the natural circadian rhythm by exposing yourself to natural daytime light and avoiding screens at night
- doing as much as you can to get quality sleep
- managing stress and anxiety
- exercising regularly
- eating a balanced diet
- contacting your doctor regarding any new symptoms or symptoms that are disruptive to your daily life
Read about how to improve your sleep quality here.
The hypothalamus is a small structure in the brain that is responsible for many important processes in the body, including regulating sleep, appetite, and growth. The hypothalamus works by sending signals for different hormones to be released in response to internal and external stimuli that it interprets.
The two main hormones of the hypothalamus are antidiuretic hormone and oxytocin, but it is also responsible for many other hormones.
It can be difficult to pinpoint precise symptoms of a disorder affecting the hypothalamus because it affects so much in the body. However, it is best to contact a doctor for any changes in appetite, weight gain or loss, intolerance to heat or cold, feeling excessively hot or cold, or growth issues.
Some hypothalamus disorders are treatable, but management will depend on what exactly is causing the disorder and what symptoms it is causing.
In general, leading a healthy lifestyle, minimizing stress, getting enough sleep, and eating a balanced diet can help support the hypothalamus.