The short answer
A pituitary tumors evaluation may include hormone testing, eye testing when needed, MRI, and specialist assessment. The goal is to confirm the exact diagnosis and gather information that changes care.
Evaluation may include hormone testing, eye testing when needed, MRI, and specialist assessment.
Not every person needs every possible test.
Planning may depend on hormone activity, size, symptoms, growth, vision, and pituitary function.
A specialist review can clarify an uncommon or unexpected diagnosis.
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The full explanation.
What brings pituitary tumors to light
Symptoms depend on whether the tumor makes extra hormones. Nearly all pituitary tumors can cause headaches and vision problems, whether or not they produce hormones. The pituitary gland sits close to the nerves that carry sight. A prolactin-making tumor can cause missed periods or breast milk production in women. In men, it can lower sex drive or cause erection problems. A growth-hormone tumor can cause enlarged hands, feet, and facial features over time, a condition called acromegaly. An ACTH-making tumor can cause weight gain, easy bruising, and other signs of a condition called Cushing syndrome.
The tests that confirm it
Blood tests check hormone levels, including prolactin, growth hormone, and ACTH. The specific pattern points toward the tumor type. MRI is the imaging test of choice for the pituitary gland. It shows soft tissue detail that other scans do not. This includes exactly how close the tumor sits to the nerves for vision. A formal vision test checks whether the tumor is already pressing on those nerves, even before you notice symptoms yourself.
Why "functioning" versus "nonfunctioning" matters
Some pituitary tumors make no extra hormones at all. Doctors call these nonfunctioning. NCI says most pituitary tumors are functioning ones, so nonfunctioning tumors are the smaller group. These are usually found because of their size, pressing on nearby structures, rather than from hormone symptoms. Functioning tumors, which do make hormones, are usually identified by their specific hormone pattern on blood tests, even when small.
What blood hormone levels do and don't tell you
A high hormone level supports the diagnosis, and points toward the tumor type. It does not, by itself, tell you the tumor's exact size. It also can't show how close the tumor sits to your vision nerves. That is what MRI is for. The two tests answer different questions and are usually needed together.
How long the wait usually takes
Turnaround is set by your center, not by a national rule. Vision testing is often discussed during the visit itself. Hormone blood tests and the MRI report usually follow later, and some centers can go over the scan at the same appointment. For tissue taken at surgery, NCI gives a rough guide: the pathologist's report usually reaches the doctor within 10 days of the operation. Ask who will call you, and when.
What to ask your team
- Is my tumor functioning or nonfunctioning, based on my hormone levels?
- What does the MRI show about size and closeness to my vision nerves?
- Does my vision test show any early changes?
- Would medicine alone treat this, or is surgery being considered?
- How urgent is treatment, given what my scans show?
When to get help sooner
- Call 911 or go to an emergency department if a severe headache arrives all at once alongside double vision, loss of vision, a drooping eyelid, or vomiting. Rarely a pituitary tumor bleeds or loses its blood supply, called pituitary apoplexy, and that is treated as an emergency.
- Call your care team the same day if your side vision starts closing in, colours look washed out, or you begin seeing double over hours to days rather than weeks.
- Call your care team within a day or two if clear, salty-tasting fluid drains from your nose, or you feel newly exhausted, cold, and faint. Those point to hormone levels that need checking rather than waiting.
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Common questions
What symptoms bring pituitary tumors to light?
Nearly all pituitary tumors can cause headaches and vision problems, whether or not they produce hormones, because the gland sits close to the nerves that carry sight. Beyond that, symptoms depend on which hormone is being made. A prolactin-making tumor can cause missed periods or breast milk production in women, and lowered sex drive or erection problems in men. A growth-hormone tumor can cause acromegaly, and an ACTH-making tumor can cause Cushing syndrome.
Which tests confirm it?
Blood tests check hormone levels including prolactin, growth hormone and ACTH, and the specific pattern points toward the tumor type. MRI is the imaging test of choice for the pituitary gland, because it shows soft tissue detail other scans do not, including exactly how close the tumor sits to the nerves for vision. A formal vision test checks whether the tumor is already pressing on those nerves, even before you notice symptoms yourself.
What is the difference between a functioning and a nonfunctioning tumor?
Some pituitary tumors make no extra hormones at all, and doctors call these nonfunctioning; NCI says most pituitary tumors are functioning ones. Nonfunctioning tumors are usually found because of their size, pressing on nearby structures, rather than from hormone symptoms. Functioning tumors, which do make hormones, are usually identified by their specific hormone pattern on blood tests, even when small.
Can a blood test tell me how big the tumor is?
No. A high hormone level supports the diagnosis and points toward the tumor type, but it does not by itself tell you the tumor's exact size, and it cannot show how close the tumor sits to your vision nerves. That is what MRI is for. The two tests answer different questions and are usually needed together.
How long do the results take?
Turnaround is set by your center, not by a national rule, so ask when each result is expected. Vision testing is often discussed during the visit itself. Hormone blood tests and the MRI report usually follow later, and some centers can go over the scan at the same appointment. If tissue is taken at surgery, NCI puts the pathologist's report to the doctor at typically within 10 days of the biopsy or operation.
Questions to ask your doctor
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Sources last checked: 2026-08-13 what this meansLast updated: 2026-08-17Next planned review: 2027-07-22
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How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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