Browse through glands, hormones and endocrine conditions.


calcium EDTA

a calcium salt used to ‘mop up’ excess calcium in the bloodstream.


a drug that blocks the production of thyroid hormones; used in the treatment of hyperthyroidism to reduce thyroxine levels.

Carpal tunnel syndrome

numbness, ‘pins and needles’ and pain in the hands and wrist, particularly around the thumb; caused by pressure on the median nerve in the wrist.


opacity in the lens of the eye leading to impaired vision or blindness. Cataracts are more frequent in the elderly and in people with diabetes.

central nervous system

consists of two major structures: the brain and spinal cord.

central node dissection

a surgical procedure, performed alongside removal of the thyroid gland, where surrounding lymph nodes are surgically removed along with the thyroid gland.


the neck or opening of the womb. During labour the cervix opens to allow the foetus to be delivered.

chorionic villus sampling

a procedure carried out during early pregnancy to obtain tissue from the placenta for genetic testing. The process comes with a slightly increased risk of miscarriage.


describes a condition that is long term or one that progresses slowly. Examples of chronic conditions are asthma, eczema and type 1 diabetes mellitus.

cognitive behavioural therapy

(CBT) a specific type of talking therapy where a therapist helps the patient to look at connections between their thoughts, feelings, symptoms and behaviour.

computerised tomography

(CT) a type of scan used to create detailed images of the inside of the body. It involves X-rays and a computer. Also known as a CAT scan or computed tomography.


the point at which a sperm successfully fertilises an egg and an embryo is formed.


describes a condition that is present at birth.

congenital heart disease

condition affecting the heart that is present at birth.

connective tissue

a type of tissue made from collagen and fatty cells within a jelly-like lattice. Connective tissue functions to support organs, fill the spaces between organs, and form tendons and ligaments.

contraceptive pill

a hormone drug taken by women to prevent ovulation and therefore to stop a pregnancy occurring (contraception). There are several different types of pill; the ‘combined’ pill contains oestrogen and progesterone; the ‘mini’ pill contains progesterone-only.

corpus luteum

a temporary endocrine gland formed from the ruptured ovarian follicle (which enclosed the egg) after an egg is released at ovulation. The corpus luteum produces the hormones progesterone and oestradiol (an oestrogen).


hormones secreted from the cortex of the adrenal gland that include glucocorticoids (e.g. cortisol), mineralocorticoids (e.g. aldosterone) and androgens (e.g. testosterone).


a glucocorticoid hormone produced by the adrenal glands. Cortisol is the main glucocorticoid in most animal species but corticosterone is higher in animals such as amphibians, rodents, reptiles and birds.

Crohn’s disease

a chronic condition in which tissues become inflamed; particularly affects the walls of the small intestine, causing strong pains, constipation and vomiting.


Calcitonin is a hormone that is produced and released by the C-cells of the thyroid gland. Its biological function in humans is to have a relatively minor role in calcium balance.


Cholecystokinin is a gut hormone released after a meal, which helps digestion and reduces appetite.

Corticotrophin-releasing hormone

Corticotrophin-releasing hormone is the main element that drives the body's response to stress. It is also present in diseases that cause inflammation. Too much or too little corticotrophin-releasing hormone can have a range of negative effects.


Cortisol is a steroid hormone that regulates a wide range of processes throughout the body, including metabolism and the immune response. It also has a very important role in helping the body respond to stress.

Carcinoid tumour

Carcinoid tumours are slow-growing tumours that arise from specialised cells that release hormones.

Childhood-onset growth hormone deficiency

Childhood-onset growth hormone deficiency is a condition where the pituitary gland fails to produce enough growth hormone during childhood. With early diagnosis and treatment, children generally achieve relatively normal height and development.

Circadian rhythm sleep disorders

Circadian rhythm sleep disorders occur when the circadian clock in the brain, which drives daily behavioural and physiological rhythms, is not synchronised with 'real' local time. This can result in abnormal sleep patterns, sleep loss and fatigue.

Congenital adrenal hyperplasia

Congenital adrenal hyperplasia is an inherited disorder that results in low levels of cortisol and high levels of male hormones, causing development of male characteristics in females, and early puberty in both boys and girls.


Craniopharyngiomas are rare, slow-growing benign brain tumours which most commonly occur above the pituitary gland, but occasionally are found within the bony cup containing the pituitary gland.

Cushing's disease

Cushing's disease is the collection of clinical symptoms and signs resulting from a pituitary tumour that causes excessive amounts of the hormone cortisol to be released by the adrenal glands.

Cushing's syndrome

Cushing's syndrome is the name given to the collection of signs and symptoms that occur when the body is exposed to too much of the hormone cortisol.