How is acromegaly diagnosed?

Acromegaly is not an easy diagnosis, and it is usually missed by primary care doctors. Some of the signs and symptoms of acromegaly are very distinctive. Others are subtle and can be missed or misinterpreted. They are not always recognized as acromegaly because they develop so slowly. Once the diagnosis is suspected, you are usually referred to a specialist in hormonal disorders (endocrinologist).

Blood tests are used to help confirm the diagnosis. Measurement of IGF-1 level is considered the most reliable test for acromegaly. Another test measures levels of IGF-binding protein-3 (IGFBP-3), a protein that interacts with IGF-1. This test is used sometimes to help confirm the diagnosis of acromegaly.

Some health care providers measure what is called “glucose nonsuppressibility.” Blood glucose (sugar) suppresses growth hormone. The level of growth hormone in your blood is measured after you drink a sugary drink. The resulting high blood sugar level suppresses the growth hormone level in healthy people but not in people who have too much growth hormone.
 
A CT scan or MRI of the head is done to look for a pituitary tumor.