How Do You Diagnose Acromegaly?

Medically Reviewed on 10/13/2022
How Do You Diagnose Acromegaly
Acromegaly is typically diagnosed by an oral glucose tolerance test with concurrent GH measurement, also called a GH suppression test

Acromegaly is a rare endocrine (hormonal) disorder caused by an excess of growth hormone (GH) levels in the body. 

Due to the insidious nature of the disease, diagnosis based on symptoms is often delayed. People often have already developed systemic problems at the time of diagnosis, leading to higher morbidity and early death. 

Acromegaly is typically diagnosed by an oral glucose tolerance test with concurrent GH measurement, also called a GH suppression test. Serum insulin-like growth factor 1 levels are indicated as the initial screening test for people with suspected acromegaly.

What tests are used to diagnose acromegaly?

A complete medical history and physical examination are required to make a diagnosis of acromegaly. If you have risk factors, symptoms, and a family history of acromegaly, your doctor may recommend blood and imaging tests to confirm a diagnosis. Medical imaging and laboratory tests are typically done in tandem to confirm or rule out the presence of this rare disease.

Confirmation of disease may be made through biochemical testing

  • Insulin-like growth factor 1 (IGF-1)
  • Growth hormone (GH) measurement through oral glucose tolerance test
  • Random GH testing

GH or IGF-1 measurement

Your doctor may advise you to undergo a blood test to determine the levels of GH or IGF-1 in your blood.  In this test, you fast overnight and provide a blood sample the next morning to evaluate GH and IGF-1 levels. The levels of these hormones are elevated in cases of acromegaly.

GH suppression test

This is a confirmatory approach for determining acromegaly. Blood GH levels are evaluated before and after consuming 75 grams of glucose (sugar). GH is suppressed in normal people with levels typically below 1 µg/L. The inability to properly reduce blood GH levels following glucose administration indicates acromegaly.

Imaging tests

Doctors may recommend imaging studies. These tests aid in determining the presence of pituitary gland tumors. They also aid in determining tumor size. Common radiological tests include:

  • X-rays: To detect bone thickening
  • MRI scan of the brain: Helps locate the tumor
  • CT scans: Can be used to detect non-pituitary tumors in the chest, abdomen, or pelvis.

Other tests

Other investigations to check potential complications of acromegaly include:

Acromegaly can proceed slowly over the years or decades, going unnoticed until several organ issues become apparent at about the age of 40 years. Hypertension, cardiovascular disease, type II diabetes, and arthritis are possible complications.

What are symptoms of acromegaly?

Acromegaly symptoms may occur gradually, so it can take time to detect them and seek medical treatment. However, early detection is critical because it can reduce the likelihood of developing illnesses such as diabetes or heart disease

Symptoms of acromegaly may include:

  • Changes in the hands and feet: The most common symptom of acromegaly is abnormally large hands and feet. Symptoms start with swelling. Rings, gloves, or shoes may no longer fit as you develop abnormally large extremities.
  • Facial changes: Acromegaly can also produce facial deformities. You may notice that the bones appear to be broader than before:
    • The brow or forehead may begin to expand and protrude
    • The lower jaw may expand, extend, and protrude
    • The bone in your nose may grow, making it appear larger
    • Your teeth may separate and develop gaps between them. 
    • Abnormal-looking lips and tongue are seen in a few cases
    • Because of enlarged sinuses and vocal cords, your voice may become deeper
  • Skin changes: Acromegaly can affect the skin. You may notice yourself sweating more than normal and have an unpleasant odor. The skin may thicken and become rough and oilier. People also complain about new skin tags.
  • General unwellness: Acromegaly can lead to various general symptoms such as:
  • Sexual problems

What are the potential causes of acromegaly?

Acromegaly develops due to the pituitary gland producing excessive amounts of GH and insulin-like growth factor 1 (IGF-1). Excess GH then causes other organs to produce an excessive amount of IGF-1. Excess IGF-1, in addition to stimulating tissue growth, can affect how the body stores sugar and fat from food. 

Potential risk factors of acromegaly include:

  • Tumors: Acromegaly develops when a tumor grows in the pituitary gland and secretes increased levels of GH during adulthood.  Most cases of acromegaly are caused by a noncancerous (benign) pituitary gland tumor or adenoma. As they grow, these tumors can put pressure on nearby tissues. Acromegaly is caused in some people by tumors in parts of the body, such as the lungs, pancreas, or adrenal glands.
  • Age: Acromegaly affects approximately 25,000 people in the U.S., and while it can occur at any age, it most commonly affects middle-aged adults.
  • Genetics: People who develop a pituitary tumor do not usually have a family history of acromegaly. However, pituitary tumors may be part of a syndrome due to unusual gene changes. 

If left untreated, acromegaly can lead to serious illness and even death.

What are treatment options for acromegaly?

Acromegaly can be treated with surgery, radiotherapy, drug therapy, or a combination of these treatments. The goal of the treatment is to restore normal GH levels, as this is associated with the disappearance of your symptoms and an improvement in your overall well-being. 

Surgical removal of the pituitary adenoma

Surgical removal of the pituitary adenoma can quickly relieve pressure on surrounding structures caused by large pituitary adenomas. However, only about 60% of people achieve normal growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels after surgery in the long run. As a result, medication or radiation may be required for residual disease or relapse.

  • Endoscopic transsphenoidal surgery: This is a minimally invasive surgery to remove the pituitary adenoma using an endoscope through a tiny incision in the nose or upper lip would relieve any pressure and lower the increased GH levels. The advantage of using an endoscope is the improved capacity to see the tumor in a panoramic manner and avoid missing any leftover tumor during resection.
  • Craniotomy: This method is done for complicated adenomas. Other considerations include unfavorable parasellar sinuses and internal or external carotid artery aneurysms.


Radiotherapy is considered in individuals whose tumors cannot be completely removed through surgery, recurrence after surgery, or fail to respond to medical therapy. 

  • Conventional fractionated radiotherapy: This is often used as an adjuvant to surgery to avoid recurrence or when surgery does not result in an adequate decrease of GH levels. Therapy is given daily for 5 days a week for 5-6 weeks.
  • Stereotactic radiosurgery: This is precision radiotherapy, in which high-dosage radiation is directed at the tumor while reducing damage to neighboring healthy brain structures. 

Medication to reduce GH production (drug treatment)

  • Somatostatin analogs: Prevent GH release from the tumor and injected according to severity; these may be long-acting or short-acting drugs
  • Dopamine agonists: May help lower GH levels and reduce the tumor size
  • GH antagonists: Inhibit the action of GH on body tissues and may normalize IGF-1 levels and improve symptoms; may be explored if all the other treatment options have failed to cure or control acromegaly.

Physical therapy management

Acromegaly can affect the functions of several systems. Physical therapists may provide a program that addresses the disease's musculoskeletal and neurological manifestations.

Support groups

Acromegaly can impact the quality of life and can cause significant distress. 

Talk to your doctor about joining support groups in your area and consult a psychiatrist if you experience signs of depression or other mental health issues.

Clinical trials

Clinical trials explore improved, more focused methods of preventing, detecting, treating, and curing health conditions and their complications. 

Most of the time, acromegaly is treatable. However, the condition can cause complications if left untreated. Acromegaly-related complications such as cancer and cardiovascular death are frequently the direct causes of death.

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Medically Reviewed on 10/13/2022
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