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Last reviewed: 29 Oct 2023
Last updated: 20 Oct 2022



History and exam

Key diagnostic factors

  • palpable breast tissue
  • newborn age
  • pubertal age
  • older adult age
  • accidental medication exposure in children
  • chemical substance abuse
  • acne in adult males
  • obesity
  • breast pain
  • small or soft testicles
More key diagnostic factors

Other diagnostic factors

  • erectile dysfunction or decreased libido
  • nutritional supplements
  • past history of abnormal sexual differentiation
  • delayed secondary sex characteristics
  • precocious puberty
  • weight loss and malnutrition
  • signs or symptoms of hypothalamic or pituitary disease
  • signs or symptoms of liver failure (e.g., jaundice, ascites, spiders)
  • signs or symptoms of hyperthyroidism (e.g., heat intolerance, weight loss, goiter)
  • decreased body hair
  • painless or enlarging testicular mass
  • diminished strength or muscle atrophy
Other diagnostic factors

Risk factors

  • anabolic steroid usage
  • occupational exposure to embalming fluid or oral contraceptives
  • contact with environmental phytoestrogens or phthalates
  • prostate cancer
  • gender identity disorder
  • hyperthyroidism
  • renal failure
  • cirrhosis
  • drugs that reduce testosterone synthesis
  • drugs that impair testosterone action
  • drugs that increase estrogen levels or stimulate estrogen receptors
  • drugs with complex or unknown mechanisms
More risk factors

Diagnostic investigations

1st investigations to order

  • serum TSH
  • serum creatinine
  • serum LFTs
More 1st investigations to order

Investigations to consider

  • serum total testosterone
  • serum LH
  • serum estradiol
  • serum sex hormone binding globulin (SHBG)
  • serum free testosterone
  • serum beta hCG
  • serum dehydroepiandrosterone-sulfate (DHEAS)
  • serum prolactin
  • mammogram
  • breast ultrasound
  • core biopsy of breast (if cancer suspected)
  • Testicular ultrasound
More investigations to consider

Treatment algorithm



pubertal idiopathic gynecomastia

infantile and prepubertal gynecomastia



Catherine B. Niewoehner, MD
Catherine B. Niewoehner

Professor of Medicine

University of Minnesota




CBN is an author of a number of references cited in this topic.

Peer reviewers

Dennis Styne, MD

Professor of Pediatrics

Rumsey Chair of Pediatric Endocrinology

University of California




DS declares that he has no competing interests.

Harold Carlson, MD

Professor of Medicine and Head of Endocrinology

Stony Brook University

Stony Brook



HC is an author of a reference cited in this topic.

Glenn Braunstein, MD

Professor and Chairman

Department of Medicine

Cedars-Sinai Medical Center

Los Angeles



GB declares that he has no competing interests.

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