Growth Hormone Deficiency (GHD)

What is growth hormone deficiency (GHD)?

Growth hormone deficiency (GHD, or pituitary dwarfism) is a rare condition in which your pituitary gland doesn’t release enough growth hormone (GH, or somatotropin). GHD can affect infants, children and adults. Children with GHD are shorter than expected with normal body proportions.

Hormones are chemicals that coordinate different functions in your body by carrying messages through your blood to your organs, muscles and other tissues. These signals tell your body what to do and when to do it.

Your pituitary gland is a small, pea-sized endocrine gland located at the base of your brain below your hypothalamus. It’s made of two lobes: the anterior (front) lobe and posterior (back) lobe. Your anterior lobe makes GH. It releases eight hormones in total.

People with growth hormone deficiency may have hypopituitarism and have a deficiency in other pituitary hormones, including:

• Antidiuretic hormone (ADH or vasopressin).
• Follicle-stimulating hormone.
• Luteinizing hormone.
• Thyroid-stimulating hormone (TSH).
• Adrenocorticotrophic hormone (ACTH).

What does growth hormone do?

Growth hormone (GH) acts on many parts of the body to promote growth in children. It’s essential for normal growth, muscle and bone strength and distribution of body fat.

Once the growth plates in your bones (epiphyses) have fused, GH no longer increases height, but your body still needs GH. After you’ve finished growing, GH helps to maintain normal body structure and metabolism, including helping to keep your blood glucose (sugar) levels within a healthy range.

If your body doesn’t have enough growth hormone — whether as an infant, child or adult — it can greatly affect your body, albeit in different ways depending on your age. In infants and children, GHD prevents normal growth. In adults, it causes a variety of issues, including increased body fat and elevated blood sugar levels.

What are the different kinds of growth hormone deficiency?

There are three main types of growth hormone deficiency (GHD), including:

• Congenital GHD: Congenital GHD means it’s present from birth due to a genetic mutation (change) or structural issues in the baby’s brain.
• Acquired GHD: GHD is considered to be acquired if its onset is later in life as a result of damage to your pituitary gland. Children and adults can have acquired GHD.
• Idiopathic GHD: In the medical world, “idiopathic” means there’s no known cause. Some cases of GHD have an unknown cause.

Growth hormone deficiency is also categorized by the age of onset. It has different symptoms and processes for diagnosis if you’re a child or adult when the condition begins.

How common is growth hormone deficiency?

Growth hormone deficiency (GHD) is a rare condition. About 1 in 4,000 to 10,000 children have GHD, and approximately 1 in every 10,000 people have adult-onset GHD.

What are the signs and symptoms of growth hormone deficiency?

The signs and symptoms of growth hormone deficiency (GHD) vary based on what age you are at the onset (start) of the condition.

Symptoms of growth hormone deficiency in infants and children

Growth hormone deficiency (GHD) in infants and children results in poor growth. The main sign of GHD in children is slow height growth each year after a child's third birthday. This means they grow less than about 1.4 inches in height a year.

Other symptoms of GHD in children and infants include:

• A younger-looking face than what’s expected for their age.
• Impaired hair and nail growth.
• Delayed tooth development.
• Delayed puberty.
• Low blood sugar levels (hypoglycemia) in infants and toddlers.
• A very small penis (micropenis) in newborns assigned male at birth.

Symptoms of adult-onset growth hormone deficiency

Symptoms of adult-onset GHD can be more difficult to detect. Symptoms include:

• Reduced sense of wellbeing.
• Anxiety and/or depression.
• Decreased energy levels.
• Increased body fat, especially around your belly.
• Decreased muscle tone.
• Decreased bone density, which leads to osteoporosis.
• Insulin resistance, which can lead to Type 2 diabetes.
• Increase in LDL-cholesterol and triglyceride levels, which increases your risk of heart disease.

What causes growth hormone deficiency?

The causes of growth hormone deficiency (GHD) can vary based on what age you are at the onset (start) of the condition. Some cases of GHD are considered idiopathic, meaning the cause of the condition can’t be determined.

Causes of congenital growth hormone deficiency

Congenital growth hormone deficiency (GHD) results from a genetic mutation and may be associated with brain structure issues or with midline facial abnormalities, such as a cleft palate or single central incisor.

Scientists have identified several genetic mutations that cause GHD, including:

• Isolated growth hormone deficiency type IA: This genetic mutation results in slowed fetal growth, and the infant is much smaller at birth than what’s expected. People with type IA usually have a normal response to treatment of synthetic growth hormone (GH) at first but then develop antibodies to the hormone. This prevents growth and results in a very short adult (final) height.
• Isolated growth hormone deficiency type IB: This genetic mutation is similar to IA, but the infant has some natural GH present at birth, and they continue to respond to synthetic GH treatments throughout their life.
• Isolated growth hormone deficiency type II: People with type II have very low levels of GH and short stature that varies in severity. Growth failure is usually evident in early to mid-childhood. About half of people with type II have an underdeveloped pituitary gland (pituitary hypoplasia).
• Isolated growth hormone deficiency type III: Like type II, people with type III have very low levels of GH and short stature that varies in severity. Growth failure in type III is usually evident in early to mid-childhood. People with type III may also have a weakened immune system and be prone to frequent infections.

Isolated growth hormone deficiency can have different inheritance patterns depending on the type of the condition.

Causes of acquired growth hormone deficiency

Cases of acquired growth hormone deficiency (GHD) result from damage to your pituitary gland that affects its ability to produce and release growth hormone. Children and adults can develop acquired GHD.

Pituitary damage can result from the following conditions or situations:

• Pituitary adenoma (benign tumor).
• Radiation therapy for or near your pituitary gland.
• Severe head injury or traumatic brain injury (TBI).
• A lack of blood flow to your pituitary gland.
• Accidental or unpreventable damage from brain surgery or surgery to remove a pituitary adenoma.
• Central nervous system infection.
• Infiltrative diseases, such as Langerhans cell histiocytosis, sarcoidosis and tuberculosis.
• Hypothalamus tumors that put pressure on your pituitary gland.

How is growth hormone deficiency diagnosed?

Diagnosis of growth hormone deficiency (GHD) in children most often occurs during two age ranges. The first is around 5 years of age when children begin school. This is because parents can more easily see how their child’s height compares to the height of their classmates. The second age range is around 10 to 13 years old in children assigned female at birth and 12 to 16 years in children assigned male at birth, which are the age ranges when puberty typically starts. A delay in puberty can signal suspicion of GHD.

Growth increments are the most important criteria in the diagnosis of GHD in children. Normal levels of growth usually follow a pattern, and if growth during a recorded six- to twelve-month period is within those ranges, it’s unlikely that they have a growth condition.

Adult-onset growth hormone deficiency is often difficult to detect because the symptoms are subtle and commonplace. This makes it more difficult to diagnose.

What tests will be done to diagnose growth hormone deficiency?

Healthcare providers use different tests to diagnose growth hormone deficiency (GHD) depending on if you’re a child or adult.

GHD diagnostic tests for children

Your child’s healthcare provider will review their medical history and growth charts to look for signs of impaired growth, risk factors for growth hormone deficiency and other conditions that can affect growth.

Other health conditions that can affect and prevent growth include:

• Hypothyroidism.
• Delayed puberty.
• Celiac disease.
• Undernutrition.

Since growth hormone levels in your blood normally vary greatly throughout the day, a simple blood test can’t determine a GH deficiency. Because of this, your child’s provider may order the following tests to help diagnose GHD and/or to rule out other conditions that affect growth:

• X-rays: Their provider may order an X-ray of their hand to check bone growth (bone age) and assess growth potential.
• Blood tests and other laboratory tests: Certain blood tests can help rule out other conditions that affect growth or help diagnose GHD. Specific blood tests include insulin-like growth factor (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3).
• Growth hormone stimulation test: This is the main test that providers use to diagnose GHD. During the test, your child will receive medications that should stimulate their pituitary gland to release GH. Their provider then takes blood samples to measure GH levels in their blood and sends them to the lab for testing. If the blood test results reveal that their GH levels didn’t rise to an expected level, it can mean that their pituitary gland isn’t making enough GH.
• Magnetic resonance image (MRI): Your child’s provider may order an MRI (imaging test) of their head to look for issues with their pituitary gland or brain, to help determine the cause of GHD.

GHD diagnostic tests for adults

One of the most common tests for diagnosing growth hormone deficiency in adults is the insulin tolerance test. Insulin is a natural hormone your pancreas makes.

During this test, your provider will give you an injection of synthetic insulin to lower your blood sugar level. They will then take blood samples and send them to a lab for testing in order to measure the amount of growth hormone in your blood.

When your body experiences low blood sugar (hypoglycemia), it normally releases growth hormone. If your blood tests reveal lower-than-normal levels of growth hormone than what’s expected for an insulin tolerance test, it confirms growth hormone deficiency.

Other tests may include:

• Glucagon stimulation test.
• Macimorelin stimulation test.
• Arginine stimulation test.
• Clonidine stimulation test.

How is growth hormone deficiency treated?

Treatment for growth hormone deficiency (GHD) in both children and adults involves synthetic growth hormone (recombinant human growth hormone) injections (shots) given at home. People with GHD most often need a daily shot.

Synthetic growth hormone treatment is long-term, often lasting for several years. It’s essential to see your healthcare provider regularly to make sure the treatment is working and to see if you need to adjust your dose of medication.

If you or your child have deficiencies in other pituitary hormones, you or they will also need treatment to correct those deficiencies.

Side effects of growth hormone deficiency treatment

Mild to moderate side effects of growth hormone injections for the treatment of growth hormone deficiency (GHD) are uncommon. They include:

• Headaches.
• Muscle pain or joint pain.
• Mildly underactive thyroid gland (mild hypothyroidism).
• Swelling of your hands and feet.
• Progression of spine curvature in people with scoliosis.

Rare but serious side effects of GHD treatment include:

• Severe headache with vision problems.
• Hip dysplasia (when your thigh bone doesn’t fit together with your pelvis as it should).
• Pancreatitis (inflamed pancreas).

If you’re experiencing any of these symptoms, it’s important to talk to your healthcare provider. They may need to adjust your medication dose.

What are the risk factors for growth hormone deficiency?

Unfortunately, most cases of growth hormone deficiency (GHD) aren’t preventable. Certain risk factors can increase you or your child’s likelihood of developing acquired GHD, including:

• Cancer treatment before reaching adult height.
• Radiation to your head or brain.
• Total body irradiation.
• Surgery to your brain, especially the central region of your brain where your pituitary gland is located.

If any of these risk factors apply to you or your child, it’s important to talk to your healthcare provider about the signs and symptoms of GHD to look out for.

What is the prognosis (outlook) for growth hormone deficiency?

For children with growth hormone deficiency (GHD), the earlier the condition is treated, the better the chance that a child will grow to near-normal adult height. Many children gain four or more inches during the first year of treatment and three or more inches during the next two years of treatment. The rate of growth then slowly decreases.

People with adult-onset GHD generally have a good prognosis and can lead a healthy life if GHD is treated properly.

What are the complications of growth hormone deficiency?

Left untreated, growth hormone deficiency in children may lead to short stature (height) and delayed puberty.

Despite proper treatment, people with adult-onset growth hormone deficiency have an increased risk of heart disease and stroke. Healthy living, such as eating a balanced diet and participating in routine exercise, can help reduce this risk.

People with adult-onset GHD also have a higher risk of developing osteoporosis. Because of this, they have a higher risk of developing bone fractures from minor injuries or falls. To decrease these risks, it’s important to have a diet that’s rich in calcium and to take vitamin D supplements, as recommended by your healthcare provider.

When should I see my healthcare provider about growth hormone deficiency?

There are many reasons for slow growth and below-average height in children. At times, slow growth is normal and temporary, such as right before puberty starts. If you’re concerned about your child’s rate of growth, see a pediatric endocrinologist (children’s hormone specialist) or healthcare provider. They can help find out if your child’s rate of growth is cause for concern.

If you’re an adult and are experiencing symptoms of growth hormone deficiency (GHD), talk to your healthcare provider.

If you or your child have been diagnosed with GHD, you’ll need to see your healthcare provider regularly to make sure your treatment is working properly.

A note from Cleveland Clinic

If you’re noticing a lack of growth in your child, it’s important to talk to their healthcare provider as soon as possible. While it may be unlikely that growth hormone deficiency (GHD) is the cause, any concerning changes are worth evaluating. People with GHD who are diagnosed early have the best outlook and usually lead healthy lives. If you have any questions about what to expect with your child’s growth, don’t be afraid to reach out to their provider. They’re there to help.