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PubMed This is a summary of 18 peer-reviewed journal articles Updated
Endocrinology

Symptoms & Warning Signs: Recognizing Prolactinoma

At a Glance

The symptoms of a prolactinoma depend on the tumor's size and your sex. Women often experience irregular periods and milky breast discharge, while men frequently notice a drop in sex drive. Large tumors can also cause headaches and vision loss by pressing on nearby brain structures.

Symptoms of a prolactinoma can vary widely depending on your sex, the size of the tumor, and how long your hormone levels have been elevated. Because the symptoms often mimic other common conditions, many people—especially men—experience a delay in diagnosis until the tumor has grown larger [1][2].

Hormonal Symptoms: The Effect of High Prolactin

Hormonal symptoms are caused by hyperprolactinemia (too much prolactin in the blood). Prolactin is known as the “milk hormone,” and when it is too high, it disrupts the normal balance of sex hormones [3][4].

Symptoms in Women

In women of reproductive age, the symptoms are often noticed early because they directly affect the menstrual cycle [5][6].

  • Irregular Periods: This may include amenorrhea (periods stopping entirely) or oligomenorrhea (infrequent or very light periods) [5][7].
  • Infertility: High prolactin prevents the normal release of eggs (ovulation), making it difficult to get pregnant [5][6].
  • Galactorrhea: This is the production of a milky breast discharge in someone who is not pregnant or breastfeeding [5][7].

Symptoms in Men

In men, the symptoms are often more subtle or may be dismissed as signs of aging or stress, which can lead to a later diagnosis [5][8].

  • Sexual Dysfunction: This includes a significant drop in libido (sex drive) and erectile dysfunction (ED) [5][9].
  • Direct Effects: Interestingly, high prolactin can cause ED even if a man’s testosterone levels are still in the normal range [9][10].
  • Physical Changes: Long-term high prolactin can lead to reduced muscle mass or, in some cases, enlarged breast tissue (gynecomastia) [4][2].

Mass Effect Symptoms: Physical Pressure

When a tumor grows larger than 10 millimeters (a macroadenoma), it can physically press against nearby structures in the brain. These are known as mass effect symptoms [4][5].

  • Headaches: These are often described as a dull pressure, sometimes felt behind the eyes or at the temples [4][11].
  • Vision Changes: The pituitary gland sits directly below the optic chiasm (where the optic nerves cross). If the tumor presses upward, it can cause bitemporal hemianopsia—a loss of the outer half of the field of vision in both eyes [11][12]. Patients with macroadenomas near the optic chiasm often need a formal visual field test (perimetry) by an ophthalmologist [11].
  • Neurological Issues: In rare cases of very large tumors, pressure can lead to double vision or drooping eyelids [4][12].

Systemic Effects: Bone Health

Prolactinomas don’t just affect your reproductive system; they can also impact your skeleton. Chronic hyperprolactinemia is a known risk factor for decreased bone mineral density (BMD) [13][14].

  • Osteoporosis and Osteopenia: High prolactin acts as a “double hit” to the bones. It indirectly lowers bone density by reducing sex hormones (estrogen and testosterone) and may also directly interfere with bone-building cells [15][14].
  • Fracture Risk: This loss of bone strength can lead to an increased risk of fragility fractures, particularly in the spine [16][17].
  • Higher Risk for Men: Studies suggest that men with prolactinomas may be at an even higher risk for long-term bone impairment than women, possibly due to the longer duration of high prolactin before diagnosis [18].

Monitoring bone health is an important part of long-term care, even after your prolactin levels have been brought under control [7][18].

Return to Home

Common questions in this guide

What are the first signs of a prolactinoma in women?
In women, the earliest signs are often related to the menstrual cycle. This can include irregular or completely stopped periods, difficulty getting pregnant, and unexpected milky discharge from the breasts known as galactorrhea.
Why is a prolactinoma often diagnosed later in men?
Men typically experience subtle symptoms like a significant drop in sex drive or erectile dysfunction. Because these signs are easily mistaken for normal aging or stress, men often aren't diagnosed until the tumor grows large enough to cause headaches or vision problems.
Can a prolactinoma cause headaches and vision loss?
Yes, if the tumor grows larger than 10 millimeters, it is called a macroadenoma. At this size, it can physically press against the optic nerves and surrounding brain tissue, causing dull headaches and a specific type of peripheral vision loss.
How does a prolactinoma affect bone health?
Chronically high prolactin levels lower the production of essential sex hormones like estrogen and testosterone. This hormonal imbalance acts as a double hit to your bones, leading to decreased bone mineral density and an increased risk of osteoporosis and fractures.
Do I need to see an eye doctor if I have a prolactinoma?
If you have a larger tumor or are experiencing headaches and peripheral vision issues, you should see an ophthalmologist. They can perform a formal visual field test to see if the tumor is pressing upward on your optic chiasm.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on my tumor's size, am I at risk for 'mass effect' symptoms like vision loss or headaches?
  2. 2.Since I have had high prolactin for a while, should I have a DEXA scan to check my bone density?
  3. 3.For men: If my testosterone levels are normal but my libido is low, is the prolactin itself the cause?
  4. 4.For women: How soon after starting treatment should I expect my menstrual cycle to become regular again?
  5. 5.Should I see an ophthalmologist for a formal visual field test (perimetry)?

Questions For You

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Related questions

Why Are Prolactinomas Diagnosed Later in Men?

References

References (18)
  1. 1

    Advances in Drug Treatments for Male Patients with Prolactinomas.

    Wang DP, Zhou HY, Zhang Y, et al.

    Neuroendocrinology 2025; (115(8)):657-677 doi:10.1159/000546443.

    PMID: 40505642
  2. 2

    Diagnosis, misdiagnosis and management of hyperprolactinemia.

    Healy ML, Smith TPP, McKenna TJ

    Expert review of endocrinology & metabolism 2006; (1(1)):123-132 doi:10.1586/17446651.1.1.123.

    PMID: 30743775
  3. 3

    Pediatric prolactinoma: initial presentation, treatment, and long-term prognosis.

    Hoffmann A, Adelmann S, Lohle K, et al.

    European journal of pediatrics 2018; (177(1)):125-132 doi:10.1007/s00431-017-3042-5.

    PMID: 29168011
  4. 4

    GIANT PROLACTINOMA. A CASE REPORT.

    Šulavíková Z, Krásnik V

    Ceska a slovenska oftalmologie : casopis Ceske oftalmologicke spolecnosti a Slovenske oftalmologicke spolecnosti 2023; (79(3)):143-148 doi:10.31348/2023/20.

    PMID: 37344216
  5. 5

    [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
  6. 6

    Approach to the Patient With Dopamine-Resistant Microprolactinoma.

    Glezer A, Stumpf MAM, Queiroz NL

    The Journal of clinical endocrinology and metabolism 2026; (111(3)):879-891 doi:10.1210/clinem/dgaf624.

    PMID: 41234156
  7. 7

    Do nothing but observe microprolactinomas: when and how to replace sex hormones?

    Bonert V

    Pituitary 2020; (23(3)):307-313 doi:10.1007/s11102-020-01039-x.

    PMID: 32274622
  8. 8

    Hemoglobin decline as a signal for hyperprolactinemia onset prior to prolactinoma diagnosis in hypogonadal men.

    Rudman Y, Duskin-Bitan H, Richter I, et al.

    Andrology 2023; (11(7)):1398-1407 doi:10.1111/andr.13428.

    PMID: 36897756
  9. 9

    Prolactin impairs erectile function via eNOS suppression independently of testosterone.

    Cheng X, Xiao Y, Qiu D, et al.

    Toxicology and applied pharmacology 2025; (504()):117532 doi:10.1016/j.taap.2025.117532.

    PMID: 40848920
  10. 10

    Increase in Testosterone Levels and Improvement of Clinical Symptoms in Eugonadic men With a Prolactin-secreting Adenoma.

    Carlier L, Chanson P, Cazabat L, et al.

    Journal of the Endocrine Society 2024; (8(9)):bvae135 doi:10.1210/jendso/bvae135.

    PMID: 39109291
  11. 11

    [Differential diagnosis and treatment of pituitary adenomas].

    Hlaváč M, Sommer F, Karpel-Massler G, et al.

    HNO 2019; (67(4)):307-318 doi:10.1007/s00106-019-0629-3.

    PMID: 30790007
  12. 12

    Trigeminal Neuralgia as an Unusual Isolated Symptom of Pituitary Adenoma: Case Report and Review of the Literature.

    Gurcan O, Gurcay AG, Kazanci A, et al.

    Turkish neurosurgery 2016; (26(1)):180-3 doi:10.5137/1019-5149.JTN.12495-14.1.

    PMID: 26768887
  13. 13

    [Hyperprolactinaemia and bone mineral density].

    Kostrzak A, Męczekalski B

    Polski merkuriusz lekarski : organ Polskiego Towarzystwa Lekarskiego 2015; (39(230)):122-5.

    PMID: 26319389
  14. 14

    Relationship between antipsychotic medication, serum prolactin levels and osteoporosis/osteoporotic fractures in patients with schizophrenia: a critical literature review.

    De Hert M, Detraux J, Stubbs B

    Expert opinion on drug safety 2016; (15(6)):809-23 doi:10.1517/14740338.2016.1167873.

    PMID: 26986209
  15. 15

    Effect of Hyperprolactinemia on Bone Metabolism: Focusing on Osteopenia/Osteoporosis.

    Yun SJ, Sang H, Park SY, Chin SO

    International journal of molecular sciences 2024; (25(3)) doi:10.3390/ijms25031474.

    PMID: 38338751
  16. 16

    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
  17. 17

    Drug-induced Hyperprolactinemia Results in Atypical Atypical Fracture.

    Lee I, Son DW, Park JH, Park JH

    Hip & pelvis 2021; (33(2)):102-107 doi:10.5371/hp.2021.33.2.102.

    PMID: 34141697
  18. 18

    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

This page provides educational information about the common symptoms and warning signs of a prolactinoma. It is not a substitute for professional medical advice, and you should consult an endocrinologist for a proper evaluation.

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