What is the endocrine system?
Hormones are chemical signals which are secreted through the blood stream and are necessary for our body to function properly. They help to regulate processes in the body, such as our appetite, weight control, growth, fluid balance, feminisation and virilisation.
The endocrine system is the network of glands in our body that are responsible for this hormone production. These endocrine glands consist of the pituitary gland, pineal gland and hypothalamus in the brain; adrenal glands above the kidneys; thyroid and parathyroid glands in the neck; pancreas; ovaries in women, and testes in men. Other organs in the body such as the stomach, liver and intestines also secrete hormones related to digestion and are considered part of the endocrine system.
What is an endocrine disorder?
When any of our endocrine glands do not function properly, it can show up as a variety of symptoms signalling an endocrine disorder. Symptoms will depend on the type of hormones involved and degree of the hormonal imbalance. As our hormones can affect multiple organs across large parts of our body, symptoms can range from minimal to severe. But if left untreated, endocrine disorders can result in serious consequences, including death.
Treatment of endocrine disorders depends on the specific disorder and is usually focused on adjusting and normalising hormone levels. This is often achieved using medications or synthetic hormones. In more severe cases, or when the underlying cause is a tumour, surgery or radiation therapy may be required to achieve hormonal balance.
Common endocrine conditions
Common endocrine disorders include diabetes mellitus, Graves' disease or hyperthyroidism (overproduction of the thyroid hormone), Hashimoto's thyroiditis or hypothyroidism (underproduction of the thyroid hormone), Cushing's syndrome (high cortisol or stress hormones over an extended period of time), acromegaly (overproduction of growth hormone), Addison's disease (underproduction of hormones by the adrenal glands), and prolactinoma (overproduction of prolactin by the pituitary glands).
This may all sound very complex, but they can be effectively managed by your GP. Especially for the following conditions:
Diabetes is one of the most common chronic diseases in the world and is characterised by high blood glucose (sugar) levels.
Diabetes is caused when the body is unable to produce enough of the hormone insulin in the pancreas (type 1 diabetes), or when the body has reduced organ sensitivity to insulin (type 2 diabetes).
Type 2 diabetes is more common in adults, and the majority of patients do not have noticeable symptoms. It is usually diagnosed by routine blood tests or during a health screening. In severe cases, tell-tale symptoms of diabetes include excessive urination volume (polyuria), waking up during the night to urinate (nocturia), excessive thirst (polydipsia), blurred vision, and weight loss.
While there is no cure for diabetes, the condition can be managed to reduce the impact of symptoms and complications. Patients who are able to control their diabetes well with medication or lifestyle changes typically experience fewer complications. In instances of poorly controlled diabetes, patients will be at risk of heart attack(s), stroke, or even death. Other complications include eye problems (diabetic retinopathy); foot issues such as nerve damage (diabetic neuropathy) and ulcers, as well as diabetic kidney disease.
This is why it is very important that patients with diabetes adhere to their doctors’ management plan and follow-up. GPs will be able to prescribe treatment plans which will involve lifestyle modifications that include moderating the intake of alcohol, regular exercise, quitting smoking, and diet control. Most patients with type 2 diabetes also require medication (oral tablets or injections) while patients with type 1 diabetes require life-long insulin injections.
Hyperthyroidism occurs when an overactive thyroid gland produces too much thyroid hormones. While thyroid hormones are important for the body’s ability to regulate its metabolism (how the body uses and stores energy), overproduction of the hormone can cause problems.
Common symptoms of hyperthyroidism include anxiety, irritability, insomnia, weakness or fatigue, tremors, heat intolerance, palpitations, weight loss or diarrhoea. For women, hyperthyroidism can lead to irregular or absent menstrual periods.
The most common cause of hyperthyroidism is Graves’ disease, where the body’s immune system produces an antibody that stimulates the excessive production of hormones in the thyroid gland. Other causes include thyroid nodules (lumps), thyroiditis (inflammation of the thyroid gland), or taking too much thyroid hormone medication (usually for hypothyroidism).
Treatment of hyperthyroidism involves medication, radioactive iodine, or surgery. Your GP will determine the most suitable course of treatment based on the underlying cause and severity of hyperthyroidism, and will take into consideration patient preferences.
Hypothyroidism is caused by insufficient production of thyroid hormone by the thyroid gland. The most common cause of hypothyroidism is Hashimoto’s disease, where the body’s immune system produces an antibody that attacks the thyroid gland. This leads to an underactive thyroid gland with reduced or no production of thyroid hormones. Other causes include medical treatments for hyperthyroidism, such as surgical removal of the thyroid or radioactive iodine treatment.
Patients with mild hypothyroidism may not experience any symptoms, while patients with more severe hypothyroidism may experience fatigue, weight gain, cold intolerance, dry and thickened skin, swelling of the tongue, hoarseness, coarse hair, brittle nails, a slower heart rate, shortness of breath during exercise, and constipation. Hypothyroidism may also cause irregular or heavy periods in women.
Treatment for hypothyroidism is focused on normalising thyroid hormone levels. This is achieved through thyroid hormone replacement with synthetic hormone tablets.
4. Thyroid nodules (lumps)
Thyroid nodules are lumps in the thyroid gland which are usually detected incidentally on routine physical examination by the doctor, health screening, or during a radiologic procedure (CT scans of the lung or neck, carotid ultrasonography, PET scans) to investigate another medical condition. However, some thyroid nodules may be big enough to be visible, or cause compressive symptoms such as difficulty breathing or swallowing, and hoarseness of voice.
There are several causes of thyroid nodules – these include overgrowth of normal thyroid tissue, fluid collection (cysts), chronic inflammation of the gland, iodine deficiency or thyroid cancer. It is particularly important to check any thyroid nodules to rule out cancer. Fortunately, most thyroid nodules are benign and do not cause any symptoms. Only a small percentage of thyroid nodules (4 – 6.5%) are cancerous.
Treatment options depend on the type and size of the thyroid nodule. Small benign nodules can be followed up with regular ultrasound imaging. Suspicious nodules should be biopsied to exclude cancer, and confirmed cancerous nodules should be removed surgically.
5. Low testosterone
Low testosterone (testosterone deficiency syndrome/male hypogonadism) is a common condition that affects approximately 25% of men aged 45 and older. It is important to diagnose and treat low testosterone levels because of the correlation between low testosterone and multiple chronic diseases, such as type 2 diabetes, hypertension, arthritis, heart disease, stroke, lung disease, and depression.
Unfortunately, many patients with low testosterone are not diagnosed because of the difficulty in identifying the signs and symptoms as these are usually dependent on the age of onset, and severity of the deficiency. Signs of testosterone deficiency typically includes low energy, low libido, erectile dysfunction, depressed mood, poor concentration and memory, irritability, small genitalia, reduced body/facial hair, decreased muscle mass, and enlarged breast tissue (gynecomastia).
Causes of low testosterone levels can include disease (such as infection or trauma) of the testes or brain (hypothalamus or pituitary gland). Other causes include alcohol abuse, liver disease, kidney failure, inflammatory conditions such as sarcoidosis, HIV/ AIDS, and side effects of medication such as opioids or chemotherapy.
Treatment of low testosterone is via testosterone replacement therapy. This can be given in several ways – intramuscular injections, testosterone patches, or testosterone gels.
Early treatment is key
As with most diseases, early detection and treatment of endocrine disorders can help you better manage the disease and its symptoms. If you are concerned that you may be suffering from hormonal imbalance or other hormone-related diseases, do seek your GP’s advice.
Article contributed by Dr Edwin Chng, Parkway Shenton medical director at Parkway Shenton, One Raffles Quay