The human body relies on chemical messengers, called hormones, to function properly. Injury to the brain can affect the production and activity of hormones, causing wide-ranging symptoms that can affect physical health, mental well-being and overall quality of life.
What are hormones?
Hormones are chemical messengers in our body that help us to keep a stable internal environment, for example stopping us from getting too hot or too cold.
Other things that hormones control are:
hunger and thirst;
sleep/wake cycles;
growth;
sexual and reproductive function;
mood;
energy, among others.
This process of keeping the body’s internal environment stable through the delicate balance of hormones is called homeostasis.
There are many hormones, produced and controlled by glands in different parts of the body. This system of hormone production, release and monitoring across the body is known as the endocrine system.
The brain has a key role in the endocrine system. Within the brain are areas that are responsible for making and releasing hormones. The pituitary gland is one such area and is known as the master gland. It is located at the base of the brain and is responsible for controlling glands throughout the body.
Some important hormones that the brain produces are listed below:
Adrenocorticotropic hormone
This helps to produce the ‘stress hormone’ cortisol, which makes our bodies respond to stressful situations.
Growth Hormone (GH)
This controls body growth in children, including muscle mass and body fat. In adults it is important for metabolism, muscle and bone health, and overall energy levels.
Melatonin
This controls our body’s cycle of sleeping and waking up, known as the body’s circadian rhythm.
Serotonin
This controls our mood and helps us to feel happy. Serotonin has a range of other functions, including helping with sleep, blood clotting, movement and digestion.
Vasopressin, also known as Antidiuretic Hormone (ADH)
This helps to balance water and blood pressure in the body. Problems with ADH levels can cause a condition known as Arginine Vasopressin deficiency (AVD). More information on AVD is provided below.
There are various other hormones produced by the brain that are not included in the above list but have equally important roles in maintaining the body’s internal environment.
How does a brain injury affect hormones?
The key areas of the brain responsible for producing, releasing and monitoring hormones are:
Hypothalamus
This area sits deep within the brain and links the endocrine system with the nervous system. It has a key role to play in the process of homeostasis.
Pituitary gland
This tiny gland is located at the bottom of the brain. It produces hormones that are responsible for multiple bodily functions, as well as controlling other glands throughout the body. For this reason, it is often called the ‘master gland’.
Pineal gland
This is located deep within the brain and is involved in producing the hormone melatonin, which is involved in our sleep/wake cycle.
These parts of the brain can be injured through accidents (including seemingly ‘minor’ accidents that cause a concussion/mild traumatic brain injury), assaults, falls, stroke, developing a tumour, cyst or other medical complications. Such injuries can affect the delicate balance of hormone activity within the body, causing a wide range of issues.
The issues experienced will depend on the specific hormone affected and the severity of the injury. For example, problems with melatonin production may cause a brain injury survivor to struggle with getting to sleep at night.
What are the symptoms of hormonal imbalances after brain injury?
Many of the symptoms of hormonal imbalances can be difficult to distinguish from the effects of the brain injury itself, such as depression, mood swings, fatigue, headaches, problems with vision, sexual difficulties and problems with cognition.
Other symptoms that are more specific to hormonal imbalances include:
Arginine Vasopressin deficiency (AVD) – causing increased thirst and excessive urination.
Constipation
Dry skin
Fatigue
Increased sensitivity to cold
Hot flashes
Irregular periods/loss of normal menstrual function
Low blood pressure/dizziness
Vomiting
Insulin resistance
Weight loss
Muscle weakness
Pale appearance
Reduced body hair
Reduced fertility
Reduced libido/interest in sex
Erectile dysfunction
The presence of these symptoms can help with identifying whether someone’s brain injury has affected their hormone levels. However, symptoms can be mild or may be due to other health problems. This can make it difficult to identify or diagnose hormonal imbalances after brain injury. As a result, hormonal imbalances may remain undiagnosed after the injury.
Due to the problem of underdiagnosis, some people may live for a long time with hormonal imbalances after brain injury without even realising it. Check through the list of symptoms above, including those similar to the common effects of brain injury, and talk to your GP if you have any concerns about these having developed in the weeks, months or years after your brain injury.
How are hormonal imbalances after brain injury diagnosed and treated?
If someone is experiencing symptoms after brain injury such as those listed in the previous section, they may need to be investigated for hormonal imbalances. This should start through a conversation with the person’s GP.
Prepare for your GP appointment by making a list of your symptoms and how these have affected your life. You may wish to bring a family or trusted friend along with you. If you have been keeping a ‘symptom diary’, consider bringing this along.
If appropriate, the GP may refer the brain injury survivor for further assessment with a specialist called an endocrinologist (or neuroendocrinologist).
An endocrinologist may undertake different blood tests to measure hormone levels in order to better understand the causes or symptoms that the survivor is experiencing. They may also ask the survivor to have a brain scan to examine any injury to the brain that may be causing the symptoms.
Treatment depends on the type of hormone affected and the impact of hormonal imbalances on the survivor’s life. For some, hormone replacement therapy (HRT) may be a suitable method of treatment. This aims to replace the hormones affected by the brain injury in order to restore balance to the body’s internal state. It may be possible for someone to be on several types of HRT at once. Medication may be offered to help with balancing hormones or needed to treat more specific complications of the imbalances. The endocrinologist may need to monitor the effect of HRT or medication over time.
In cases such as brain tumours, more intensive treatments such as surgery or radiotherapy may be needed. The clinical team will discuss this with the survivor and manage their treatment very carefully.
Coping with hormonal imbalances after brain injury
In many cases, hormone replacement therapy or medication will be effective enough to help the brain injury survivor cope with hormonal imbalances after their injury.
Sometimes it may be necessary to learn new ways to cope with managing the effects of hormonal imbalances, such as learning strategies for coping with fatigue or cognitive issues.
Visit Living with brain injury for guidance on coping with many of the effects of brain injury.
The Pituitary Foundation also offers guidance on living with pituitary and other hormonal imbalance conditions on their website.
Complications of hormonal imbalances after brain injury
Explore the sections below to learn more about the possible complications of hormonal balances after brain injury.
Hypopituitarism
The pituitary gland is a key brain structure involved in hormone production and management. Damage to this structure can commonly cause a condition called hypopituitarism, where the pituitary gland can no longer produce its regular hormones.
When pituitary function is disrupted after a traumatic brain injury, it is referred to as post-traumatic hypopituitarism (PTHP). PTHP can remain underdiagnosed as can be mild or difficult to distinguish from other symptoms of brain injury.
Hypopituitarism can cause many of the symptoms previously listed.
Arginine Vasopressin Deficiency (formerly known as diabetes insipidus)
The hormone responsible for sodium and water balance in the body is called vasopressin and it is known as an anti-diuretic hormone. An underproduction of this hormone can cause a condition called Arginine Vasopressin Deficiency (AVD), formerly known as diabetes insipidus. This is different to the condition diabetes mellitus, a disorder related to high blood sugars often referred to as type II diabetes. AVD causes increased thirst and excessive production of dilute urine.
Treatment of AVD involves taking anti-diuretic medication. In most cases, AVD following TBI resolves quickly after the injury, but in rare cases it can last for longer, sometimes permanently. In these cases, it may be necessary to take lifelong hormonal replacement therapy.
Growth Hormone Deficiency
Hormones are involved in body growth, including things such as muscle mass and body fat. Growth hormone deficiency (GHD) is a condition where growth hormones are not produced properly.
In children it can lead to slow height growth resulting in short stature. In adults this can cause bodily changes such as reduced muscle mass, increased weight gain (including obesity), thinning skin, reduced bone density (which can cause a condition known as osteoporosis), impaired heart function, mood changes and fatigue. These changes can be difficult to adjust to, both physically and psychologically. Self-esteem may be affected, or there may be problems with completing activities the person usually enjoys.
GHD can be treated with growth hormone replacement therapy. Regular exercise and a healthy diet might help with weight issues.
Adrenal insufficiency
Adrenal insufficiency is a condition in which the adrenal glands (small glands above the kidneys) do not produce enough of the hormone cortisol. This can cause a range of issues such as fatigue, headache, weight loss or reduced appetite, bodily pains and muscle weakness, excessive thirst, among other symptoms. An endocrinologist can help to diagnose and treat adrenal insufficiency.
Hyperprolactinemia
This is a condition in which the pituitary gland of the brain produces too much prolactin. This can cause general issues such as infertility, loss of libido, low bone mass, milky discharge from nipples, as well as some gender specific effects such as changes in menstruation and vaginal dryness in women, and erectile dysfunction, low levels of testosterone, and enlarged breast tissue in men (known as gynaecomastia).
Lifestyle struggles
Living with the symptoms of hormonal imbalances after brain injury can be very challenging. Brain injury survivors with this issue may find themselves experiencing significant struggles in aspects of life such as employment, relationships, self-esteem and activities of daily living. Mental health can be affected as a result of these struggles.
Mental health
Living with the effects of brain injury can be difficult. They can cause people to feel frustrated, depressed, anxious or even suicidal. These can be a direct result of injury to the brain but can also be experienced following imbalances to hormones in the brain that control mood.
It is important for people to reach out for support if their mental health is affected by brain injury. They can get professional support through their GP, or contact mental health helplines for support and advice, such as Samaritans. Our nurse-led helpline can also offer emotional support, a listening ear and advice on coping with a brain injury.
Counselling, talking therapies or neuropsychological support may be available through a referral from the GP or privately. These can provide more intense and specialised support for mental health.
Puberty, pregnancy and childbirth
Several hormones controlled by the brain are involved in processes related to puberty, pregnancy and childbirth. Disruptions to these hormones can cause delays in puberty onset, affect menstrual periods or fertility, or interfere with the process of having a baby.
An endocrinologist may need to closely monitor a brain injury survivor with hormonal imbalances throughout the duration of their pregnancy. Hormone replacement therapy can help with managing these issues.
If you are struggling to cope with these issues, it is important to get help. Speak to your GP or contact our helpline to talk about your experiences and feelings. If you are struggling with your mental health, consider asking your GP about getting a referral for counselling or other talking therapies.
The organisations listed on this page are provided for information purposes only. Their inclusion does not imply endorsement, recommendation, or approval by Headway. Users should make their own assessment of any organisation or service before engaging with them.
The information on this page was produced with expert support from Dr Darran McDonald, Consultant Endocrinologist & Dr Sue Jackson, Independent Chartered Psychologist and member of the Pituitary Foundation’s Medical Advisory Committee.
This information was last reviewed in 2026.
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