Medicines and Words Defined

Adrenal glands

Two triangle shaped organs which sit above your kidneys. They produce a variety of hormones which affect other parts of the body. The middle of the adrenal glands (the medulla) makes the hormones adrenaline and noradrenaline (also called epinephrine and norepinephrine). The crust of the adrenal glands (the cortex) makes the hormones aldosterone, cortisol and androgens.

Adrenaline (Epinephrine)

A hormone (also called epinephrine) which is released into the body by the adrenal glands. It is produced in response to stress or danger. It increases your heart and breathing rate, amongst other things. It is an important part of the 'fight or flight' reaction. The nervous feeling you get in your stomach before doing something in public is caused by adrenaline!

Adrenocorticotrophin Hormone (ACTH)

A hormone released by the pituitary gland, often in response to stress. It tells the adrenal glands to produce cortisol.


A hormone released by the adrenal glands, which acts on the kidneys to balance the salt and water in the body. It also affects blood pressure.


Red blood cells carry oxygen around your body. If you have anaemia, you have fewer red blood cells than normal. This can make you tired. There are many causes of anaemia, but a common cause is due to lack of dietary iron. Iron is needed for red blood cells to work, and is found in leafy green vegetables, eggs and red meat.


Androgens are a group of hormones that in boys cause male sexual characteristics (such as a deep voice and facial hair) to develop. Testosterone is an example of an androgen. Androgens are present in higher levels in men, but they are important for women as well. In a woman's body, androgens play a key role in starting puberty (stimulating hair growth in the pubic and underarm areas) and are converted into the hormone oestrogen.

Antidiuretic Hormone (ADH)

A hormone released by the pituitary gland. It acts on the kidneys to conserve water by limiting the amount of urine produced. It is also known as vasopressin.


Arthritis is a common condition which causes inflammation and pain in one or more joint.


A type of brain tumour.


The results of a hearing test. 

Autoimmune Condition

An autoimmune condition develops as a result of your immune system making a mistake, and working against the normal tissues in your body. The immune system normally works against germs to keep us healthy, but can make us unwell when it attacks the wrong cells.


A word often used to describe a tumour or condition that does not produce harmful side effects on its own. However they can sometimes cause problems if they press on other nearby organs.

Blood pressure

This is a measurement which tells your doctor or nurse how hard your heart is pumping to get your blood flowing around your body. It is measured by putting a band around your arm that gets filled with air, squeezing your arm. If it is too low, or too high it can cause problems for your health, which is why it gets checked.

Bone Mineral Density

This is a medical term for the results from a bone density scan. It checks on the strength of your bones. This measurement helps your doctor to understand whether you are at risk of broken or weak bones in the future. Some medications and conditions affect bone density which is why it needs to be monitored.


Chemotherapy is the use of special drugs, normally used to treat cancer. These drugs are very powerful, and can sometimes affect the body's normal cells as well as the cancer cells. That is why people treated with chemotherapy can lose their hair.


Inside most of the cells in your body, you have tiny thread like strands called Chromosomes, which contain your genetic makeup (genes). Most people have 23 pairs of chromosomes - one half of the pair comes from your mother, and the other half from your father. Chromosomes, along with your genes, determine how you look and how your body works.

Coeliac disease

People who have coeliac disease react to gluten. Gluten is found in many foods, which can make choosing the right thing to eat very difficult. In this condition the immune system reacts to gluten, and causes damage to the small intestine. This makes absorbing important nutrients from food difficult. People with coeliac disease are therefore at risk of malnutrition.


Confidentiality means doctors and nurses not telling anyone else what you've said to them. This means that you can speak to them privately about anything you are worried or embarrassed about, and they will not tell your parents. The only reason that your doctor or nurse might have to break confidentiality is if what you have told them makes them worried about you, or about someone else's safety. They should speak to you about this.


A congenital disorder or disease is a condition which exists from birth. Congenital conditions can be a result of genetic or environmental causes.

Congenital Adrenal Hyperplasia (CAH)

A genetic condition where there is a problem with one of body’s genes which affecting the way the adrenal glands work. The gene that doesn’t work properly causes an enzyme which turns one hormone into another to not work properly. This causes the adrenal glands to grow in size, and to not make enough of the hormone cortisol, but to make too much of the androgen hormones. 


Also known as birth control, contraception is used to prevent getting pregnant. There are many types of contraception choices (the pill, coil, implant or injection), some of which also prevent catching sexually transmitted infections (condoms).


A group of steroid hormones released by the adrenal glands. Aldosterone, cortisol and androgens are all corticosteroids. 

Corticotrophin-Releasing Hormone

Corticotrophin-releasing hormone is released by the hypothalamus to tell the pituitary to release ACTH (adrenocorticotrophic hormone). It is important in the body’s response to stress. 

Cortisol/ hydrocortisone

Cortisol is a hormone released by the adrenal glands. It is important for a variety of functions, but is particularly important for helping the body respond to stress. Hydrocortisone is the medication used to replace cortisol. 


A type of slow growing, benign brain tumour.

Desmopressin/ DDAVP

Desmopressin is the name of the drugs which act as a substitute for antidiuretic hormone/vasopressin. It causes a decrease in urine production and is used to treat diabetes insipidus. Trade names are DDAVP, Desmotabs and Desmospray.

Diabetes Insipidus

A condition characterised by great thirst and the constant need to pass urine. It is caused by a reduction in, or lack of response to antidiuretic hormone. It is an entirely different disease to Type I or II Diabetes Mellitus, which has to do with insulin and blood sugar levels.

Diabetes Mellitus

Diabetes mellitus is a very common disorder caused by the body not being able to produce or respond to the hormone insulin. This causes high levels of sugar in the bloodstream, which causes health problems. There are several types; the most common are Type I and Type II.


The process of deciding what condition someone has, by considering their signs and symptoms, medical background and from looking at the results of any tests which have been done.


Going to the toilet frequently, passing very soft or liquid poo. It has many causes including infection and inflammation of the intestines.

Endocrine System

The system of hormone-producing glands (such as the pituitary, thyroid, adrenal and the ovaries and testes) and the hormones they make. The endocrine system controls many aspects of life, including growth and reproduction.


A doctor who specialises in disorders and treatments of the endocrine system.


Fertility is the ability of a man or woman to make a baby. Fertility depends on factors such as the quality of the woman’s eggs and the man’s sperm. It can be affected in some endocrine conditions.

Follicle Stimulating Hormone (FSH)

A hormone released by the pituitary that contributes to sexual development. It works alongside LH in both men and women. In women it controls ovulation and so is important for a normal menstrual cycle and for fertility. In men it tells the testes to produce sperm.


Genes are found on the thread-like chromosomes that are in your cells. Genes are made up of your DNA. They determine the way you look, and how your body works. You inherit your genes from your parents, which is why someone might say you look like them.


Genetics is the study of how physical traits and characteristics get passed down from one generation to the next. It includes the study of genes, and how these might be involved in some inherited medical conditions.


A type of protein which is found in wheat, rye, barley and grains. Sensitivity to gluten leads to coeliac disease.

Gonadotrophin Releasing Hormone

A hormone released from nerve cells in the brain. It controls the production of LH and FSH from the pituitary gland.

Gonadotrophins (Sex Hormones)

This is a collective term for the sex hormones FSH and LH, which are hormones produced by the pituitary gland.


The term for the reproductive organs; ovaries in a woman, and testes in a man.

Growth Hormone (GH)

A hormone released by the pituitary gland which controls the rate of growth. Even after you've finished growing, growth hormone has many important effects during adult life, such as affecting your muscles, bones and energy levels. 


The muscular organ in your chest which pumps blood around your body.


Is the presence of excess hair growth in women and is commonly caused by an imbalance of hormones.


A hormone is a chemical which is made in one part of the body but passes into the bloodstream and has effects on other parts of the body. Hormones act as signals, telling the body that something needs to happen. 

Hormone Replacement Therapy (HRT)

Hormone replacement therapy (or HRT) is the replacement of certain female hormones like oestrogen and progesterone, if a woman is not producing enough of them. 


The increased production and growth of normal cells - often resulting in an organ becoming larger.


The part of the brain which controls the release of many hormones from the pituitary gland.

Immune system

This is a system including different parts of your body, such as white blood cells and lymph nodes which help protect your body from disease. The immune system has different parts which work together to fight off germs, and help you recover from illness. Sometimes the immune system makes a mistake and attacks the normal cells in the body – which results in autoimmune conditions.


A hormone released by the pancreas, in response to high blood sugar (glucose) levels. Glucose comes from the food you eat, where it enters the bloodstream. Insulin helps glucose to exit the blood and enter the body's cells where it is used as fuel for energy. If someone doesn't produce enough insulin, or cannot respond to it - they develop a condition called Diabetes Mellitus.

Insulin-like Growth Factor 1 (IGF-1)

A hormone which is released by the liver in response to Growth Hormone. IGF-1 is important in growth during childhood and as an adult. IGF-1 levels can be used to see how well your body is responding to Growth Hormone.

Intramuscular Injection

An injection deep into muscle – usually at the top of your arm, leg or bottom.


The kidneys are a pair of organs which get rid of unwanted materials from the blood. These materials are passed out of the body as urine. Kidneys also release hormones and regulate blood pressure as well as the levels of water, salts, and minerals in the body.


A type of cancer of the white blood cells, which is treated using chemotherapy.


The largest gland in the body, which sits in the top right hand corner of your abdomen. The liver has many important functions, such as detoxifying poisonous substances, regulating blood sugar levels, storing fat and breaking down carbohydrates. The liver also produces important vitamins.

Luteinizing hormone (LH)

A hormone released by the pituitary gland that contributes to sexual development. It works alongside FSH in both men and women. In females it controls ovulation and so is important for a normal menstrual cycle and for fertility. In men it stimulates the testes to produce sperm.


The time of life when a woman's ovaries stop producing hormones and eggs and she stops menstruating (having monthly bleeds, or periods). 

Menstrual Cycle

A cycle of changes that occur in a woman’s ovaries and lining of her uterus every month from when she starts puberty to the menopause. The menstrual cycle prepares a woman’s body for pregnancy, and is controlled by the levels of the hormones LH, FSH, oestrogen and progesterone. During each menstrual cycle, an egg is released by the ovaries (ovulation) and if pregnancy does not occur, the lining of the uterus is shed (menstruation).


Usually, all the cells in your body have the same copies of chromosomes and genes. Sometimes some cells have a different mix of chromosomes and genes, and this is called a Mosaic pattern - because some cells are affected and some are not.


The way in which the cells in your body use food and drink to maintain your body, and for energy to do things. Your body ‘metabolises’ food and drink, turning them into energy for cells to use. This energy can be for your daily activities, such as walking around, but also for repairing your body and for growing.


A female hormone which is produced and released by the ovaries. It is important for female sexual development – making a girl’s body into a womanly shape, and causing breasts to grow. It is also important in the development of an egg during the menstrual cycle

Ovary (Ovaries)

Two round organs which are part of the female reproductive system. They make and release eggs, and release the hormones oestrogen and progesterone.


The process by which an egg is released from the ovary in the middle of the menstrual cycle. It is triggered by a surge in LH from the pituitary gland.


The pancreas is a long, flat gland that sits behind your stomach. It produces enzymes that are important for digestion. Insulin is made in the pancreas.

Periods/ Menstruation

A period is the monthly bleeding from a woman’s as a part of the menstrual cycle. A period is also called menstruation. In most women this happens about every 28 days. Each month, in response to the hormone oestrogen the uterus (womb) builds a lining of tissue and blood to prepare it to support a pregnancy. When a pregnancy does not occur, the body gets rid of this lining by having a period. The lining blood and tissue flows out of the opening of the uterus, and passes out of the body through the vagina.

Pituitary gland

A small gland which is part of the endocrine system, located in the brain. It produces hormones, which in turn control the hormone production of many other glands in the body.

Pituitary tumour

A tumour (almost always benign) of the pituitary gland. Because of where the pituitary gland is in the brain, these tumours can sometimes cause problems with sight if they press on surrounding tissues.

Polycystic Ovarian Syndrome

A female condition characterised by an imbalance in the level of the hormones oestrogen and testosterone, having cysts on the ovaries, and not releasing an egg from the ovaries during the menstrual cycle. It can cause many symptoms including hirsutism and absent or infrequent periods.


One of the female hormones which is released by the ovaries and acts on the uterus. The levels of progesterone change during the month and have an important role in the menstrual cycle and during pregnancy. 


The time of life, normally during early teenage years, when the body begins to develop the sexual characteristics of an adult.


Radiotherapy - treatment with X-rays to destroy tumour cells. Sometimes normal cells can be damaged as well.


A hormone released by the pituitary gland. It inhibits the secretion of other hormones, including growth hormone and insulin.


Another name for growth hormone.

Subcutaneous injection

An injection under the skin.


When you are unwell, there are normally changes in your body which indicate that there is a problem - like having a fever. Symptoms are the changes you have noticed, and tell your doctor or nurse about.

Testicle (Testes)

Two oval shaped male reproductive glands that produce sperm and the hormone testosterone.


A steroid hormone from the androgen group of hormones. In men it is produced by the testes (testicles). It is important for the development of male sexual characteristics (like growing pubic hair and developing a deep voice), plays a key role in reproduction. It is also important for the maintenance of bone density and strength and for muscle growth and strength.

The Pill

The pill refers to a type of medication that contains artificial versions of the female hormones oestrogen and progesterone, which women produce naturally in their ovaries. The pill is usually used as a type of contraception, but it can also be used to replace hormones if a woman is not producing them. There are several types (for example the combined pill and the progestogen-only pill), with different amounts of female hormones in them.

Thyroid gland

A gland which lies over the windpipe below the voice box in the neck. It is part of the endocrine system and is responsible for releasing hormones that are essential to numerous body processes

Thyroid Hormone

A group of two hormones produced by the thyroid gland. They are important for normal metabolic processes and mental and physical development.

Thyroid stimulating hormone (TSH)

A hormone released by the pituitary gland, telling the thyroid gland to release thyroxine.


One of the thyroid hormones released by the thyroid gland. It is important for heart and muscle function and the development and maintenance of bones.


An abnormal swelling in or on a part of the body. Tumours can be benign or malignant.

Turner Syndrome

Turner Syndrome (TS) is a chromosome abnormality affecting only females, caused by the complete or partial deletion of the X chromosome. The incidence of TS is approximately 1:2000 live female births.

Type I diabetes

A type of diabetes which can affect children and young adults. In type I diabetes the body stops making insulin and the blood sugar (glucose) levels go very high. Insulin injections and a healthy diet are used to control the blood glucose level.

Type II diabetes

A type of diabetes which can affect any age. In type II diabetes the body stops responding to insulin and blood sugar (glucose) levels go very high. Losing weight, a healthy diet, medication and sometimes insulin injections are used to control the blood glucose level.

Uterus (Womb)

The uterus (womb) is part of the female reproductive tract. It is the muscular organ in which a baby grows, or when not pregnant sheds its lining each month

White blood cells

White blood cells are part of the immune system. They attack foreign invaders, like viruses and bacteria. There are different types of white blood cell, each with its own particular job in attacking germs.

X Chromosome

One pair of chromosomes are the sex chromosomes, and these determine the sex of a baby. In a female, there will be two X chromosomes. This is different in Turners Syndrome, where one X chromosome is missing or damaged.

Y Chromosome

One pair of chromosomes are the sex chromosomes, and these determine the sex of a baby. In a male, there will be one X chromosome and one Y chromosome.