The 6 Most Common Endocrine Diseases

Endocrine diseases are those that modify the normal secretion of hormones released directly into the blood. They usually cause nonspecific and systemic symptoms, as they affect the whole body.

Written and verified by el biólogo Samuel Antonio Sánchez Amador.

Last update: 23 June, 2023

The endocrine system is made up of a series of glands and organs that perform multiple functions. In general, these tissues are responsible for releasing hormones directly into the bloodstream, so that they reach their targets in any part of the body and have a certain effect on them. However, there are certain common endocrine diseases that prevent or hinder this process.

Some of the endocrine diseases have a very high prevalence (such as diabetes), while others are considered rare and unusual in the general population. On this opportunity, we’ll show you 8 diseases of the endocrine system. Keep reading!

What’s an endocrine disease and which are the most common?

An endocrine disease is any condition that affects the internal secretion glands, that is, those that release hormones into the blood capillaries. Among the glandular tissues that can be seen disrupted are the thyroid, pituitary gland, pineal gland, adrenal glands, parathyroid glands, hypothalamus, pancreas, and thymus.

According to the portal Rare diseases, this group of diseases usually affects the development, growth, metabolism, sexual function, and the mood of the patient. Different types of endocrine diseases can be distinguished according to their nature, as indicated in this list:

• Decreased hormonal secretion: In these cases, one (or more) of the internal secretion glands produces less hormones than it should. An example is hypothyroidism.
• Increased hormonal secretion: As you can imagine, in these cases, one of the internal secretion glands produces more hormones than it should. In contrast to the previous example, we can cite hyperthyroidism.
• The appearance of a tumor in a gland: A malignant neoplasm in a glandular tissue can disrupt the endocrine system in several ways. Thyroid cancer is the most widely reported example within this category.

Therefore, most common endocrine diseases correspond to an increase or decrease in hormonal secretion by an essential gland. Below, we’ll give you 6 examples and explain their pathological mechanism in detail.

1. Diabetes

As indicated by the United States National Library of Medicine, diabetes is the most common endocrine disease in high-income regions such as the US. The World Health Organization estimates that the prevalence of this disease has increased dramatically worldwide, as reports of cases have gone from 108 million in 1980 to 422 million in 2014.

What’s more, this organization states that 1.5 million deaths around the world during 2019 were caused directly by this clinical picture. In all cases, the diabetic patient has very high blood sugar levels, but according to its etiology, diabetes can be divided into 3 types. We’ll look at them below.

1.1 Type 1 diabetes

Type 1 diabetes is a chronic disease in which the patient has a lifelong high blood glucose level (if left untreated). The cause of the condition is unknown, but it’s believed that it could be mediated by an autoimmune mechanism: The body’s protective cells selectively attack the beta cells of the pancreas, which is responsible for producing insulin.

Insulin is a hormone that enables glucose to enter cells so that it can be used as an energy source. In its absence, sugars accumulate in the blood and cause a series of characteristic clinical signs. This type of diabetes only represents 5-10% of total cases and begins to manifest itself from childhood.

1.2 Type 2 diabetes

Without a doubt, this is the most common variant of this clinical picture. Approximately 1 in 11 people in the world are diabetic and 90% of them suffer from type 2 or acquired diabetes, as indicated by the IntraMed portal. In this case, the beta cells of the pancreas do work, but the adipocytes, hepatocytes, and muscle cells don’t respond correctly to insulin.

Generally, type 2 diabetes develops over time and is fueled by obesity and a sedentary lifestyle. Some of the most common symptoms are:

• Increased thirst and frequent urination
• Extreme hunger and weight loss for no apparent reason
• Fatigue and blurred vision
• Irritability
• Sores that take time to heal and frequent infections, especially in the excretory system

Unlike the previous variant, mild symptoms of type 2 diabetes are usually treated with changes in diet and encouraging the patient to exercise more frequently. However, if blood sugar levels don’t drop or continue to rise, oral antidiabetics or, ultimately, insulin may be required.

1.3 Gestational diabetes

As its name indicates, gestational diabetes is a diabetic condition that occurs for the first time during pregnancy in women who’ve never suffered from this disease before. It’s one of the most common endocrine diseases when it comes to pregnancy, as studies indicate, it can complicate 8 to 12% of gestational periods.

It’s unknown exactly what causes the development of diabetes in a pregnant woman, but certain risk factors have been recorded in the medical field. Among them, we find the following:

1. Excess weight, obesity, and lack of physical activity
2. Gestational diabetes or prediabetes experienced in previous pregnancies
3. Polycystic ovary syndrome
4. Ethnicity-dependent genetic predisposition

With this condition, there’s a certain risk that the baby’s larger than normal at the time of delivery, as it has been “supercharged” with an excess of sugars in the blood. Therefore, if gestational diabetes isn’t well controlled, a cesarean section is often necessary.

2. Hypothyroidism

Hypothyroidism is one of the most common endocrine diseases that affect the thyroid gland. This glandular tissue in the shape of a butterfly is located in the neck (just above the internal portion of the clavicle) and, in a normal situation, it controls the rhythm of many body activities at the metabolic level.

In hypothyroidism, the thyroid gland does not produce enough thyroid hormones (T3 or triiodothyronine and T4 or thyroxine). This event can stem from many causes, including the following:

• Hashimoto’s disease: An autoimmune disorder in which the body’s protective cells directly attack the thyroid, mistaking it for a threat. Its incidence ranges from 0.3 to 1.5 cases per 1000 people per year and is more common in girls between 30 and 50 years of age.
• Thyroiditis: Corresponds to the inflammation of the thyroid gland. In turn, this picture can be caused by many underlying diseases.
• Congenital hypothyroidism: The thyroid gland doesn’t produce enough hormones at birth or even before birth. It affects 1 in 1,500 to 2,000 babies.

Be that as it may, the symptoms of hypothyroidism are general: Fatigue, increased sensitivity to cold, dry skin, swelling of the face, hoarseness, muscle weakness, joint pain, and slow heart rate, among others. The usual treatment for hypothyroidism involves daily use of the synthetic thyroid hormone levothyroxine, known as hormone replacement therapy.

3. Hyperthyroidism

This clinical picture is the opposite of hypothyroidism because here, the thyroid produces too much thyroid hormone. This endocrine disease can have several causes, among which the following stand out:

• Graves’ disease: In this clinical picture, the immune system attacks the thyroid, but instead of causing it to produce less hormones, it leads to the opposite pathological event. It affects approximately 0.5% of the world population and is the direct cause of 50 to 80% of hyperthyroidism cases.
• Thyroid nodules: These are solid or fluid-filled lumps that form inside the thyroid. They’re not neoplastic in the vast majority of cases, and they don’t usually cause very obvious symptoms, as indicated by the Mayo Clinic.
• Excess iodine: Excess iodine can cause the thyroid gland to become overactive, as this is one of the essential compounds in the synthesis of thyroid hormones.

Regardless of their origin, the symptoms are as follows: Nervousness, fatigue, trouble tolerating heat, irregular heartbeat, diarrhea, weight loss, mood swings, and goiter (enlarged thyroid). In this case, antithyroid drugs are used to stop hormonal production, and beta-blockers to alleviate the physical symptoms.

4. Thyroid cancer

Unfortunately, cancers are clinical pictures that should be listed on almost every list of common diseases, endocrine or otherwise. In this case, the thyroid cells undergo mutations in their DNA, which causes them to not respond to normal patterns of senescence and division. Therefore, they grow uncontrollably and form a malignant neoplastic tumor.

There are up to 5 types of thyroid cancers, but scientific sources estimate that they represent only 1% of all types of cancer. Even so, their prevalence seems to increase by 4% each year and in recent times, they’ve earned the position of being the eighth pathological picture of this type in women. An estimated 44,280 adults in the US will be diagnosed with thyroid cancer this year.

Although the symptoms vary according to the location and type of tumor, the following general clinical signs can be cited:

• A bump on the neck and close to the Adam’s apple. The mass corresponds to the place where the thyroid is located.
• Hoarseness and difficulty swallowing and breathing.
• Sore throat and neck.
• A persistent cough that can’t be explained by other common conditions, such as the flu or cold.

If the tumor is very small, immediate treatment may not be required. However, most people with this type of cancer require a total or partial removal of the thyroid, which may be accompanied by the resection of the lymph nodes in the neck. After this procedure, often lifelong hormone replacement therapy is needed.

5. Addison’s disease

Addison’s disease is a disorder that occurs when the adrenal glands don’t produce enough hormone content. In a normal situation, this glandular tissue is responsible for synthesizing glucocorticoids (such as cortisol), mineralocorticoids (aldosterone), and sex hormones, such as androgens and estrogens.

As a result of damage to the kidneys or their adjoining areas, the hormonal balance in this area is lost in the clinical picture. Although it’s one of the most common endocrine diseases, its global prevalence is low, affecting 4-6 people per 100,000 inhabitants. Some of the symptoms that this condition causes are the following:

1. Extreme fatigue, unexplained weight loss, and a marked decrease in appetite
2. Low blood pressure, which can lead to fainting
3. Nausea, diarrhea, and vomiting
4. Depression, irritability, sadness, and other behavioral symptoms
5. Body hair loss and sexual dysfunction (in the female gender)

The causes of Addison’s disease can be multiple. For example, the immune system sometimes mistakenly attacks the adrenal glands, destroying them and thus preventing the synthesis of hormones. Bleeding, tumors, and certain infectious conditions also trigger this pathology in some cases.

6. Cushing’s disease

As the last representative of the most common endocrine diseases, we cite Cushing’s disease. This disease is characterized by hyperactivity of the pituitary gland, which is responsible for secreting the hormone adrenocorticotropin (ACTH). This, in turn, promotes the growth of the adrenal glands and the secretion of corticosteroids.

Cushing’s disease is usually caused by an adenoma (benign tumor) in the pituitary tissue in 60-70% of cases. The most obvious clinical signs are summarized in the following list:

1. Selective obesity in the upper part of the body, while the arms and legs appear thin
2. A “Full moon” face: Round, red, and puffy
3. A slow growth rate in infants
4. Acne, purple stretch marks, and thin epidermis prone to bruising
5. Weak muscles and an intolerance to exercise

If swelling is the cause of hyperstimulation of the pituitary, its surgical resection will be the first step of treatment. After this clinical event, continuous or lifelong hormone replacement therapy is usually required, as the body stops producing certain essential hormones on its own.

The most common endocrine diseases and their prevalence

In this list, we’ve presented you with 8 common endocrine diseases, with special emphasis on the 3 main types of diabetes, as without a doubt, this is the most widespread condition in the general population. Although Addison’s disease and Cushing’s disease tend to lead these types of issues, it’s important to emphasize that their absolute prevalence is very low compared to other conditions.

Therefore, we can conclude that endocrine diseases (except diabetes) aren’t common diagnoses, much less among young and middle-aged people. In any case, due to the multitude of symptoms and complications they generate, all of them must be treated promptly. If you’ve seen yourself reflected in these lines, don’t hesitate to go to the doctor.