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8.3. Endocrine system diseases


As we saw when we talked about diet-related diseasesdiabetes occurs when the pancreas does not produce enough insulin. As a consequence, the concentration of glucose in the blood increases.

The characteristic symptoms of diabetes are excess urination (polyuria), feeling thirsty (polydipsia) and appetite (polyphagia), and weight loss. Untreated sick people feel exhausted and have difficulty healing wounds.

The diabetic (insulin-dependent) person has to regularly inject insulin.

Leading a healthy life, exercising and eating a healthy diet, controlling the level of glucose in the blood, are healthy habits that make it easier for us to fight this disease.

Insulina y glucagón: hormonas que, si funcionan mal, provocan diabetes.

Modificado a partir de By Rhcastilhos (Own work) [Public domain], via Wikimedia Commons

Animation: What Happens in Type 1 Diabetes?.


The goiter is produced by an increase in the size of the thyroid. The cause of this abnormal growth may be due to a deficiency of iodine in the diet or a problem in the amount of thyroid hormones produced.

The main symptom is the large size of the neck, compressing the windpipe and causing difficulty in breathing and swallowing.


By Dr. J.S.Bhandari, India (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons


The hyperthyroidism, or thyrotoxicosis, is a hyperactivity of the gland thyroid, thereby increasing the concentration of thyroid hormones in the produced blood.

These hormones stimulate the basal metabolism, which is why symptoms such as nervousness, insomnia, weight loss, bright eyes, excessive sweating, etc. appear.

Treatment is usually based on the administration of medications that cause the decrease in hormones, although it can also be surgical or with iodine irradiation.


The Hypothyroidism occurs when thyroid does not produce enough thyroid hormone. It is usually caused by a thyroid disorder or a lack of iodine in the diet.

As the cells do not have enough thyroid hormone, the metabolism slows down, you gain weight, you feel colder, you feel tired and drowsy, bradycardia, hair loss.

Treatment consists of the administration of the synthetic thyroxine hormone.

Antes y después de una mujer que ha sido tratada para el hipotiroidismo

See page for author [Public domain], via Wikimedia Commons


The hirsutism is a condition which causes excessive hair growth, mainly women, in unusual areas of women such as the chin, shoulders, chest, ...

Although it can be idiopathic, it is usually due to an excess of male hormones (androgens), by problems in the adrenal glands, in the ovaries or in the pituitary.

Treatment consists of the administration of drugs that inactivate this excess of hormones.

Cuadro de José Ribera titulado "La mujer barbuda", en el que una mujer con hirsutismo da el pecho a su hije

José de Ribera [Public domain], via Wikimedia Commons

Cushing's syndrome

The Cushing syndrome occurs when the adrenal glands produce excess hormone cortisol.

Its main symptoms are obesity, high blood pressure, and growth retardation in children.

Its treatment consists of the inactivation by drugs of this excess of hormones.

Pituitary dwarfism

The dwarfism is a problem for which an individual has a height considerably lower than the average. There are several possible causes of dwarfism, such as achondroplasiaTurner syndrome, or pituitary dwarfism.

The pituitary dwarfism is the set of alterations produced as result of a deficiency in the secretion of growth hormone (GH).

Treatment consists of external supply of genetically engineered growth hormone.

Enanismo: Cuadro de Digo Velázquez, "El Bufón don Sebastián de Morra"

Diego Velázquez [Public domain], via Wikimedia Commons


The gigantism occurs when the pituitary gland produces, during childhood, excess production of growth hormone.

When excess growth hormone is produced in adulthood, it is called acromegaly.

Its main symptom is exaggerated growth, and its treatment would consist of the administration of drugs that inactivate the hormone.

Below you have a small documentary about the tallest man in history. It measured 2.72 meters. Look at wikipedia to learn more about his life.

An Aragonese who was famous for his stature was Fermín Arrudi, born in 1870, and who with his 2.29 meters was known as the Giant of Sallent, traveling half the world showing his body.


The osteoporosis is a disease of the skeletal system in which decrease bone mass that forms both of the proteins that constitute the matrix and of mineral salts of calcium containing.

It can have many causes, but one of them is the cessation of estrogen production after menopause, leading to brittle and broken bones.

Its treatment consists of the ingestion of calcium and external supply of estrogens.

Activity: Hormonal diseases.


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Biology and Geology teaching materials for Compulsory Secondary Education (ESO) and Baccalaureate students.