Diabetes and Hypoglycemia
The three main types of diabetes—type 1, type 2 and gestational—are all defined as metabolic disorders that affect the way the body metabolizes, or uses, digested food to make glucose, the main source of fuel for the body. Hypoglycemia, characterized by a blood sugar (glucose) level that is too low to fuel the body’s normal functioning, may be a condition by itself, a complication of diabetes or another disorder.
Diabetes is characterized by a failure to secrete enough insulin to compensate for the degree of insulin resistance. Because insulin is needed by the body to convert glucose into energy, these failures result in abnormally high levels of glucose accumulating in the blood. Diabetes may also be a result of other conditions, such as genetic syndromes, chemicals, drugs, pancreatitis, infections, viruses or other illnesses.
You can find more information about diabetes services on the Johns Hopkins Comprehensive Diabetes Center website.
Diabetes: What You Need to Know
Type 1 diabetes is an autoimmune disease in which the immune system attacks and destroys the cells in the body that produce insulin. The rate of type 1 diabetes is rising worldwide, with the greatest increase occurring in children younger than age 5.
Type 2 diabetes is a metabolic disorder resulting from the body's inability to make enough insulin or to properly use insulin. Type 2 diabetes is the most common type of diabetes.
Gestational diabetes mellitus occurs when a hormone made by the placenta prevents the body from using insulin effectively. It is not caused by a lack of insulin but by other hormones produced during pregnancy that can make insulin less effective. Gestational diabetic symptoms disappear following delivery.
People under age 45 should consider testing for prediabetes or diabetes if they have a body mass index (BMI) greater than or equal to 25 kg/m2 and have several risk factors.
People over age 45 should be tested for prediabetes or diabetes. If a first blood glucose test is normal, individuals should be retested every three years.
The thyroid gland, an endocrine gland located in the neck just below the Adam's apple, produces hormones that play a key role in regulating blood pressure, body temperature, heart rate, metabolism and the reaction of the body to other hormones. The two main hormones produced by the thyroid are thyroxine and triiodothyronine. It also produces calcitonin, which stimulates bone cells to add calcium to bone and regulate calcium metabolism.
Thyroid Disorders: What You Need to Know
Hypothyroidism, when the thyroid gland underproduces hormones, may lead to tiredness, weight gain, depression, abnormal bone development, mental retardation and stunted growth. The most common cause is the body's immune reaction to itself, when it produces antibodies that attack the thyroid gland. One such autoimmune disorder, Hashimoto's thyroiditis, is an inflammation of the thyroid gland. Treatment of other thyroid conditions may induce hypothyroidism.
Hyperthryoidism, thyroid gland overproduction, can lead to Grave’s disease, accelerated metabolism, sweating, arrhythmia (irregular heart beat), weight loss and nervousness.
Thyroid adenomas, small growths or nodules, start in the cell layer that lines the inner surface of the thyroid gland. The adenoma itself may secrete the thyroid hormone, and if it secretes enough thyroid hormone, it may cause hyperthyroidism. Thyroid adenomas may be treated if they cause hyperthyroidism, and treatment may include surgery to remove part of the thyroid (the overactive nodule).
Cancer of the thyroid occurs more often in people who have undergone radiation to the head, neck or chest. However, it may also occur in those without any known risk factors. There are four main types of thyroid cancer: papillary thyroid cancer, follicular thyroid cancer, anaplastic thyroid cancer and medullary thyroid cancer. Most thyroid cancer can be cured with appropriate treatment.
Adrenal glands are small, triangular glands located on top of both kidneys that interact with the hypothalamus and pituitary gland in the brain. The hormones secreted by the adrenal glands affect metabolism, chemicals in the blood and certain body characteristics.
When adrenal glands produce too much or too little of these hormones, they cause a shift, which can have a negative effect on an individual’s health, including his or her ability to cope with physical and emotional stress.
Adrenal Disorders: What You Need to Know
Symptoms of hormone overproduction, one cause of Cushing’s disease, can include: upper body obesity; round face; increased fat around the neck or a fatty hump between the shoulders; thinning arms and legs; fragile and thin skin; stretch marks on the abdomen, thighs, buttocks, arms and breasts; bone and muscle weakness; severe fatigue; high blood pressure and blood sugar; irritability; and anxiety. In women, excess facial hair and irregular or stopped menstrual cycles can also occur, and men might also experience reduced sex drive and infertility.
Symptoms of hormone underproduction, the cause of Addison’s disease, can include: weakness, fatigue, dizziness, dark skin, weight loss, dehydration, lack of appetite, muscle aches, nausea, vomiting, diarrhea, low blood pressure and low sugar levels. Women may also experience irregular or absent menstrual periods.
A pheochromocytoma is an adrenal gland tumor that secretes too much epinephrine (adrenaline) and norepinephrine (noradrenaline), hormones responsible for regulating heart rate and blood pressure, among other functions. Pheochromocytomas are tumors of the central portion of the adrenal gland (the adrenal medulla). The vast majority of these tumors are benign and will not come back after they are removed.
Treatment depends on which hormone is affected and may include surgical removal of growths or the adrenal gland(s) itself, as well as radiation, chemotherapy and drugs that block excessive production of certain hormones.
The pituitary gland is an endocrine gland located just off the hypothalamus at the base of the brain. Known as the “master gland,” it secretes hormones that regulate the functions of other glands, as well as growth and several body functions. Overactivity and underactivity of the pituitary gland can cause a range of conditions, including those that affect sexual development, thyroid function, growth, skin pigmentation and adrenocortical function.
There is no obvious cause for pituitary tumors. Some might be caused by stimulation from the hypothalamus, which signals the pituitary gland to make hormones.
Pituitary Disorders: What You Need to Know
Acromegaly occurs when the pituitary gland produces excess growth hormones. Affecting mostly middle-aged adults, symptoms vary and can include swelling of hands and feet, coarsening of facial features and body hair, increasing perspiration and body order, irregular menstrual cycles and breast milk production in women, and impotence in men. More than 95 percent of acromegaly cases are caused by benign tumors on the pituitary gland.
Diabetes insipidus results from insufficient production of ADH, a hormone that helps the body conserve the correct amount of water. Diabetes insipidus is not related to the more common type of diabetes, diabetes mellitus, although some of the symptoms—excessive thirst, excessive urine production and dehydration—are similar.
Empty sella syndrome is characterized by an enlarged bony structure that houses the pituitary gland at the base of the brain; additional symptoms, although there may also be none, can include impotence, reduced sexual desire and irregular menstruation.
Hypopituitarism, also called an underactive pituitary gland, affects the anterior lobe of the pituitary gland, usually resulting in a partial or complete loss of functioning of that lobe.
Most pituitary tumors are benign. However, because of the location of the pituitary gland, many pituitary tumors press against the optic nerves, causing vision problems. In addition, pituitary tumors that produce excess amounts of hormones overstimulate other endocrine glands and cause symptoms specific to the overproduced hormone.
Metabolic Bone, Calcium and Parathyroid Disorders
Metabolic bone diseases are disorders of bone strength usually caused by abnormalities of minerals (such as calcium or phosphorus), vitamin D, bone mass or bone structure, with osteoporosis being the most common. While bone loss does occur as a part of the normal aging process, there are many diseases, medications and conditions that can increase the risk of bone failure. When untreated, osteoporosis can lead to fragility fractures, bone deformities and serious disability.
In some cases, problems with the parathyroid glands can lead to bone disorders. These small glands are located in the neck and produce parathyroid hormone, or PTH. The job of PTH is to regulate calcium and phosphorus in the blood, as well as assist with blood clotting, enzyme synthesis and muscle function. There are many different kinds of parathyroid disease (primary, secondary, tertiary) for which our physicians can assist with diagnosis and treatment.
Metabolic Bone, Calcium and Parathyroid Disorders: What You Need to Know
Men and women of all ages can suffer from skeletal disorders. The most common include osteoporosis, osteopenia, osteomalacia, vitamin D deficiency and parathyroid disorders.
Those at high risk for bone loss and osteoporosis include older individuals, as well as those with small body size, history of fractures, steroid use, intestinal diseases, organ transplants and kidney disorders.
Fragility fractures (breaking a bone when falling from standing height of less) that occur after menopause or in older men are not normal and should lead to a metabolic bone evaluation including bone density testing.
Current screening recommendations indicate that women over age 65, men over age 70 and anyone age 50 or older who has had a fracture should undergo a DXA (dual energy X-ray absorptiometry) scan.
Bone density screening with DXA and laboratory testing is also is recommended for individuals with conditions that predispose them to bone loss such as hormonal prostate or breast cancer treatments, parathyroid or thyroid disorders, certain medications such as steroids, those with significant height loss, transplant patients and women who underwent menopause before age 45.
The “building blocks” of bone include calcium, vitamin D, phosphorus and protein. Diseases or conditions that cause deficiencies in any of these things can lead to bone loss and fracture.
Parathyroid gland hypersecretion may lead to brittle bones that fracture easily and stones in the urinary system.
Parathyroid gland hyposecretion may lead to muscle tetany (involuntary muscle contraction), which is caused by low levels of calcium in plasma.
The diagnosis and management of metabolic bone, calcium and parathyroid disorders can be complex and requires a partnership between the patient and endocrinologist to determine the appropriate treatment plan.
Lipids, or lipoproteins, are the fats found circulating in the bloodstream. They include low-density lipoproteins (LDL), high-density lipoproteins (HDL) and triglycerides.
LDL, or "bad" cholesterol, can contribute to the formation of plaque buildup in your arteries, known as atherosclerosis, which is linked to increased risk of heart attack and stroke. HDL, or "good" cholesterol, helps to remove cholesterol from the blood, preventing the fatty buildup and formation of plaque.
Lipid Disorders: What You Need to Know
Cardiovascular disease is caused by atherosclerosis and is particularly sensitive to lipid levels.
Cholesterol screenings look at the fats in blood and help identify those at risk of heart disease.
Elevated triglyceride levels may be caused by medical conditions such as diabetes, hypothyroidism, kidney disease or liver disease. Dietary causes may include high alcohol intake and foods containing cholesterol, saturated fat and trans fat.
There are a number of easy ways to lower your LDLs, including avoiding foods high in saturated fat, dietary cholesterol and excess calories; exercising; maintaining a healthy weight; and stopping smoking.
Medical treatment may include modification of risk factors and cholesterol-lowering medications such as statins.
Gonadal and Menstrual Disorders
Both men and women have gonads. In males, they are the testes, or testicles, the male sex glands that are part of the male reproductive system. They are located behind the penis in a pouch of skin called the scrotum.
The female gonads, the ovaries, are a pair of reproductive glands. They are located in the pelvis, one on each side of the uterus, and they have two functions: They produce eggs and female hormones.
Gonadal and menstrual disorders stem primarily from hormone dysfunctions; the ovaries and testes produce many of the same hormones, but in different amounts.
Gonadal and Menstrual Disorders: What You Need to Know
In men, “gonadal disorders” refer to disorders of the testes, or gonads, which are the organs in men that produce sperm and hormones, including testosterone.
Gonadal disorders in men can lead to serious complications, including hypogonadism—a result of low testosterone production—sexual dysfunction and infertility. Gonadal disorders are often treated with hormone replacement therapy.
Low testosterone can be identified through a blood test typically performed in the morning, when levels are highest, as testosterone levels can drop by as much as 13 percent during the day.
Menstrual disorders in women are usually caused by imbalances in estrogen and progesterone or are related to an overactive or underactive thyroid.
Menstrual disorders can include abnormally early or late onset of puberty, very light periods, very heavy periods and irregular or absent periods. They can also affect ovulation, including increasing the risk for ovarian cyst development, problems during pregnancy and the early onset of menopause.