Skip to content
How It Works
Explore
Resources Ask a Question
Who It's For
Patients
Decode results, prep for appointments, weigh options.
Caregivers & advocates
Carry the research load for someone you love.
Providers & clinicians
Resources for patients in your practice.
Log In Ask a Question
PubMed This is a summary of 13 peer-reviewed journal articles Updated
Endocrinology · Prolactinoma

Recognizing the Signs: Symptoms of Prolactinoma

At a Glance

Prolactinoma symptoms depend on the tumor's size and hormone production. Women often experience irregular periods and unusual breast milk production, while men may notice a drop in sex drive. Larger tumors can press on the optic nerve, causing headaches and peripheral vision loss.

The symptoms of a prolactinoma can be divided into two main categories: those caused by the hormone prolactin itself (hormonal symptoms) and those caused by the physical size of the tumor (mass effect symptoms) [1][2]. Because prolactin levels affect the reproductive system, symptoms often differ significantly between men and women.

Hormonal Symptoms in Women

In women, the excess prolactin often mimics the state of pregnancy or breastfeeding, which disrupts the normal menstrual cycle.

  • Amenorrhea or Oligomenorrhea: This is the loss of regular menstrual periods or having very infrequent periods [1].
  • Galactorrhea: This is the production of breast milk in women who are not pregnant or breastfeeding [1].
  • Infertility: High prolactin levels can prevent ovulation, making it difficult to become pregnant [1].

Hormonal Symptoms in Men

Because men do not have obvious early warning signs like missed periods, their tumors are often diagnosed much later. By the time of diagnosis, men are more likely to have larger tumors (macroprolactinomas) [3][1].

  • Sexual Dysfunction: This includes a significantly diminished libido (sex drive) and erectile dysfunction [1][4].
  • Physical Changes: Over time, low testosterone (caused by the high prolactin) can lead to a loss of body hair and, in some cases, the development of breast tissue (gynecomastia) [4].
  • Infertility: High prolactin can also reduce sperm count and quality.

Mass Effect Symptoms (Macroprolactinomas)

When a tumor grows larger than 10 millimeters (macroprolactinoma), it can begin to press on the structures surrounding the pituitary gland [2].

  • Vision Loss: The most classic sign is bitemporal hemianopsia, which is a loss of peripheral (side) vision [2]. This happens because the tumor presses on the optic chiasm, the place where the optic nerves from your eyes cross [2].
  • Headaches: Persistent, dull, or pressure-like headaches are common when a tumor is large enough to create pressure within the skull [5][6].
  • Hypopituitarism: A large tumor can squash the remaining healthy parts of the pituitary gland, causing it to stop producing other vital hormones [2].

Long-Term Risks: Bone Health

If left untreated for years, the hormonal imbalances caused by a prolactinoma can lead to osteoporosis (bone loss) [7]. This happens because the high prolactin suppresses the sex hormones (estrogen and testosterone) that are necessary to maintain bone density [8]. Men and those with long-standing, untreated high prolactin are at the highest risk for this complication [8][9].

Red Flags: When to Seek Immediate Help

In rare cases, a prolactinoma can cause a medical emergency called pituitary apoplexy [10]. This occurs if the tumor suddenly bleeds or loses its blood supply, causing it to swell rapidly.

Seek emergency medical attention if you experience:

  • A sudden, “thunderclap” headache—the worst headache of your life [10][11].
  • Rapidly worsening vision or sudden double vision [10][12].
  • Sudden drooping of an eyelid [12].
  • Sudden confusion or extreme weakness.

These symptoms require immediate evaluation by a neurosurgeon or endocrinologist to prevent permanent damage [13].

Back to Home

Common questions in this guide

How do prolactinoma symptoms differ between men and women?
In women, a prolactinoma often causes irregular periods, infertility, and unusual breast milk production. Because men do not have these early menstrual warning signs, they typically experience a loss of sex drive and erectile dysfunction, and their tumors are often diagnosed at a larger size.
Can a prolactinoma cause vision problems?
Yes, if the tumor grows larger than 10 millimeters, it is called a macroprolactinoma and can press against the optic chiasm. This typically causes a loss of peripheral or side vision, making it difficult to see things to your far left or right.
Why does a prolactinoma increase the risk of osteoporosis?
High prolactin levels suppress the production of sex hormones like estrogen and testosterone. Over time, these consistently low hormone levels can weaken your bones, increasing the risk of bone density loss and osteoporosis if the tumor remains untreated.
What are the emergency warning signs of a prolactinoma?
You should seek immediate emergency medical care if you experience a sudden, severe thunderclap headache, rapid vision loss, double vision, or sudden drooping of an eyelid. These can be signs of pituitary apoplexy, a rare but serious emergency where the tumor bleeds or swells rapidly.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on my MRI, is my tumor close enough to the optic chiasm to risk my vision?
  2. 2.Are my symptoms, such as low libido or cycle changes, primarily from the high prolactin or could they be related to other pituitary hormones?
  3. 3.Should I have a bone density (DEXA) scan to check for bone loss if I've had these symptoms for a long time?
  4. 4.What is the 'red flag' plan if I develop a sudden, severe headache or vision changes after hours?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (13)
  1. 1

    [Current diagnosis and treatment of hyperprolactinemia].

    Melgar V, Espinosa E, Sosa E, et al.

    Revista medica del Instituto Mexicano del Seguro Social 2016; (54(1)):111-21.

    PMID: 26820213
  2. 2

    The Role of Surgery in the Management of Prolactinomas.

    Donoho DA, Laws ER

    Neurosurgery clinics of North America 2019; (30(4)):509-514 doi:10.1016/j.nec.2019.05.010.

    PMID: 31471058
  3. 3

    Prevalence of Hyperprolactinemia and Clinically Apparent Prolactinomas in Men Undergoing Fertility Evaluation.

    Ambulkar SS, Darves-Bornoz AL, Fantus RJ, et al.

    Urology 2022; (159()):114-119 doi:10.1016/j.urology.2021.03.007.

    PMID: 33766719
  4. 4

    Characteristics and outcomes of men with erectile dysfunction as the presenting symptom due to a lactotroph adenoma.

    Andereggen L, Tortora A, Schubert GA, et al.

    Acta neurochirurgica 2024; (166(1)):314 doi:10.1007/s00701-024-06213-9.

    PMID: 39085672
  5. 5

    Prolactinoma: Navigating the Dual Challenge of Side Effects and Treatment Strategies - A Comprehensive Review.

    Yogeeta F, Rauf SA, Devi M, et al.

    Annals of medicine and surgery (2012) 2024; (86(8)):4613-4623 doi:10.1097/MS9.0000000000002308.

    PMID: 39118737
  6. 6

    Prolactin-Secreting Lung Adenocarcinoma Metastatic to the Pituitary Mimicking a Prolactinoma: A Case Report.

    Yao H, Rui W, Zhang Y, et al.

    Neurosurgery 2019; (85(4)):E773-E778 doi:10.1093/neuros/nyy386.

    PMID: 30137505
  7. 7

    Hyperprolactinemia Due to Prolactinoma has an Adverse Impact on Bone Health with Predominant Impact on Trabecular Bone: A Systematic Review and Meta-Analysis.

    Nagendra L, Dutta D, Mondal S, et al.

    Journal of clinical densitometry : the official journal of the International Society for Clinical Densitometry 2024; (27(1)):101453 doi:10.1016/j.jocd.2023.101453.

    PMID: 38064881
  8. 8

    Persistent bone impairment despite long-term control of hyperprolactinemia and hypogonadism in men and women with prolactinomas.

    Andereggen L, Frey J, Andres RH, et al.

    Scientific reports 2021; (11(1)):5122 doi:10.1038/s41598-021-84606-x.

    PMID: 33664388
  9. 9

    Prolactinoma: A Massive Effect on Bone Mineral Density in a Young Patient.

    Sperling S, Bhatt H

    Case reports in endocrinology 2016; (2016()):6312621 doi:10.1155/2016/6312621.

    PMID: 27446618
  10. 10

    Pituitary apoplexy within a prolactin-secreting macroadenoma in a child: A rare clinical entity with radiological correlation.

    Mouhcine Y, Lahjouji O, Ouazzani H, et al.

    Radiology case reports 2025; (20(11)):5583-5589 doi:10.1016/j.radcr.2025.07.066.

    PMID: 40895003
  11. 11

    Pituitary Apoplexy Without Chiasmal Compression Presenting With Radiographic Oculomotor Nerve Compression in a Prolactinoma: A Case Report.

    Holz EA, Imran M, Reyes N, Izquierdo-Pretel G

    Cureus 2026; (18(6)):e111830 doi:10.7759/cureus.111830.

    PMID: 42535139
  12. 12

    Recovery of Cranial Nerve Deficits in Patients Presenting with Pituitary Apoplexy: A Case Series.

    Alahmari M, Alkherayf F, Lasso A, et al.

    Journal of neurological surgery. Part B, Skull base 2022; (83(Suppl 2)):e1-e6 doi:10.1055/s-0040-1722668.

    PMID: 35832969
  13. 13

    The role of intervention timing and treatment modality in visual recovery following pituitary apoplexy: a systematic review and meta-analysis.

    Brown NJ, Patel S, Gendreau J, Abraham ME

    Journal of neuro-oncology 2024; (170(3)):469-482 doi:10.1007/s11060-024-04717-z.

    PMID: 39503840

This page is for informational purposes only and does not replace professional medical advice. Always consult your endocrinologist or neurosurgeon if you experience concerning symptoms like sudden vision changes or severe headaches.

Get notified when new evidence is published on prolactin producing pituitary tumor.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.