The typical outward appearance of the disease develops very slowly, so the patient and their relatives may not notice it for years. Therefore, the diagnosis of acromegaly is delayed by an average of 5-7 years. During this time, the pituitary tumor also grows and is usually a macroadenoma by the time a diagnosis is made. Even if the outward appearance suggests acromegaly, laboratory tests are absolutely necessary for a definitive diagnosis. However, it must be understood that the person who will order and interpret all these tests is an endocrinologist. To this end, it is necessary to measure the levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) in the blood, and in those without diabetes, an oral glucose tolerance test (OGTT) should be ordered to see if the GH in the blood is suppressed. If the laboratory results indicate acromegaly, pituitary MRI imaging should be requested to reveal the adenoma. In rare cases, an adenoma may not be seen, and GH may be secreted from a source outside the pituitary gland. In such cases, the endocrinologist may order further investigations to identify this source.