Browse through glands, hormones and endocrine conditions.



of, or relating to, babies, children or young people.


the roof of the mouth, which separates the mouth from the nose.

pancreatic polypeptide

a hormone produced by the pancreas in response to changes in blood glucose levels caused by meals rich in protein, high levels of exercise and during starvation. It is important in regulating molecules secreted by the pancreas.

parasympathetic nervous system

part of the autonomic nervous system, which is not under voluntary control. It serves to slow the heart rate, increase intestinal and gland activity and relax sphincter muscles.

paraventricular nucleus

a group of nerve cells found in the front half of the hypothalamus which is linked with the rear lobe of the pituitary gland.


before new scientific findings are published, they should be read and critically reviewed by other scientists working in the area but from a different place of work. This process is called peer review.

pelvic adhesions

scar tissue that forms in the pelvic area, usually after surgery. If found in the fallopian tubes, they can cause a blockage or change in fallopian tube shape that would prevent an egg travelling down the tube.

perimenopausal period

the time during which a woman stops having menstrual periods. Periods become less regular or lighter, at first, then they eventually stop (the menopause).


of, or referring to, something on the edge or outskirts of a specific organ or body system.


a pessary is a ring-shaped medical device inserted into the vagina to provide support to the uterus and bladder. It helps to prevent urine from leaking (incontinence).


an essential salt found in every cell of the body.


refers to processes that occur naturally in the body to keep cells and tissues alive to ensure the body is functioning properly.


a treatment for muscular problems given by a trained physiotherapist that could include specific exercises, stretches or deep tissue massage.


refers to coloration of the skin and the colour of the iris within the eyes.

pituitary tumour

a growth of cells in the pituitary gland. Pituitary tumours are usually benign but can cause the gland to produce too much or too little of certain hormones, and can threaten sight if pressing on the optic nerve.


cells found within blood that stick together to help the blood to clot at the site of an injury.

positive feedback

the process that occurs after a hormone produces its response to signal for more of this hormone to be released.

positron emission tomography

(PET) a specialised type of nuclear medicine scan used to look at tissues within the body to determine if these tissues are working properly or if they are showing signs of any abnormal behavior.


an essential salt found in the body.


early. When a child develops certain features earlier than would be expected for their age.


a small, long thin instrument used in surgery to explore an area of the body.


expected long-term outcome or likelihood of recovery from a disease or medical condition.


a usually inactive form of a hormone, which needs to be converted to the active form before it has an effect in the body.

prostate-specific antigen

(PSA) a hormone produced by the prostate, which is raised in prostate cancer.


a group of molecules, formed from chains of amino acids, found within all living organisms. In the human body they form part of all tissues and organs and are involved in many processes that enable the body to function.


overproduction of skin cells mostly commonly found on the ankles, knees and elbows.


a medical professional who treats patients with psychiatric disorders such as schizophrenia, mood disorders and depression.


of or relating to the mind.


a medical professional who studies, or treats people with, disorders of the mind.


a condition affecting the mind where the patient may experience hallucinations, a change of personality and differences in the way they view the world around them.

pulmonary embolism

a blood clot or blockage in one of the blood vessels leading to the lungs. This stops blood from getting to the lungs, resulting in chest pain and shortness of breath.


The pancreas is an organ that serves two vital purposes: to aid food digestion and to produce hormones that mainly serve to control levels of energy in the blood.

Parathyroid glands

The parathyroid glands are situated in the neck and control the levels of calcium in the blood.

Pineal gland

The pineal gland is situated in the middle of the human brain and is the major site of the body's melatonin production.

Pituitary gland

The pituitary gland is a small pea-sized gland that plays a major role in regulating vital body functions and general wellbeing. It is referred to as the body's 'master gland' because it controls the activity of most other hormone-secreting glands.


The placenta is a temporary endocrine organ formed during pregnancy, which produces hormones important in the maintenance of a healthy pregnancy and in preparation for labour and breastfeeding.

Parathyroid hormone

Parathyroid hormone is secreted by the parathyroid glands and is the most important regulator of blood calcium levels.

Peptide YY

Peptide YY is a hormone made in the small intestine. It helps to reduce appetite and limit food intake.


Progesterone is a hormone released by the corpus luteum in the ovary. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy.


Prolactin is a hormone produced in the pituitary gland, named because of its role in lactation. It also has other wide-ranging functions in the body, from acting on the reproductive system to influencing behaviour and regulating the immune system.


The prostaglandins are a group of lipids made at sites of tissue damage or infection that are involved in dealing with injury and illness. They control processes such as inflammation, blood flow, the formation of blood clots and the induction of labour.

Paget's disease

Paget's disease is a common, chronic bone disorder which may have no symptoms or it may cause pain, deformity and bone fracture. Early diagnosis of symptoms and treatment with medication will help to control Paget's disease.


A paraganglioma is a rare type of tumour that forms along major blood vessels and nerves. Paragangliomas can occur in the head, neck, chest or abdomen.


A phaeochromocytoma is a tumour of the adrenal gland that produces excess amounts of hormones such as adrenaline and noradrenaline.

Pituitary apoplexy

Pituitary apoplexy is a medical emergency. It is caused by either a bleed into and/or death of an area of tissue in the pituitary gland. It is usually associated with the presence of a pituitary tumour.

Polycystic ovary syndrome

Polycystic ovary syndrome is a term that covers a spectrum of problems caused by an imbalance in the level of the body's sex hormones (oestrogen and testosterone).

Prader-Willi syndrome

Prader-Willi syndrome is a genetic disorder leading to excess hunger and obesity, lack of some hormones, developmental delay, learning difficulties and behavioural problems.


Pre-eclampsia is a condition that arises during pregnancy in which the expectant mother experiences very high blood pressure and protein in her urine; it can lead to a range of complications.

Precocious puberty

Precocious puberty is the abnormally early development of any secondary sexual characteristics: before the age of nine years in a boy and eight years of age in a girl.

Premature ovarian insufficiency

Menopause usually happens in women over the age of 45 years, but if the ovaries stop working prematurely (i.e. before the age of 40 years), this is called ‘Premature Ovarian Insufficiency’ (POI).

Premenstrual syndrome

Premenstrual syndrome (PMS) is a condition that affects women during the days leading up to her monthly period; it can cause distressing physical and emotional symptoms.

Primary hyperaldosteronism

Primary hyperaldosteronism refers to a condition in which one or both adrenal glands generate too much of a hormone called aldosterone. This causes sodium (salt) retention, leading to high blood pressure.

Primary hyperparathyroidism

Primary hyperparathyroidism is the release of too much parathyroid hormone from the parathyroid glands causing high levels of calcium in the bloodstream.


A prolactinoma is a benign tumour of the pituitary gland that produces excess amounts of the hormone prolactin. It responds well to medication and surgery is avoidable in the majority of cases.