Diagnosis

Your doctor will ask about your medical history and conduct a physical exam. Then he or she may recommend the following steps:

• IGF-1 measurement. After you've fasted overnight, your doctor will take a blood sample to measure the IGF-1 level in your blood. An elevated IGF-1 level suggests acromegaly.
• Growth hormone suppression test. This is the best method for confirming an acromegaly diagnosis. During this test, your GH blood level is measured both before and after you drink a preparation of sugar (glucose). In people who don't have acromegaly, the glucose drink typically causes the GH level to fall. But if you have acromegaly, your GH level will tend to stay high.
• Imaging. Your doctor may recommend an imaging test, such as magnetic resonance imaging (MRI), to help pinpoint the location and size of a tumor on your pituitary gland. If no pituitary tumors are seen, your doctor may order other imaging tests to look for nonpituitary tumors.