Last reviewed: 27 Sep 2021
Last updated: 01 May 2018



History and exam

Key diagnostic factors

  • decreased libido
  • loss of spontaneous morning erections
  • erectile dysfunction
  • gynaecomastia
  • infertility
  • galactorrhoea
  • micro-penis
  • small testes
  • bifid scrotum
  • cryptorchidism
  • eunuchoid proportions
  • bitemporal hemianopia
  • low trauma fractures
  • loss of height
  • anosmia

Other diagnostic factors

  • decreased energy and fatigue
  • delayed puberty
  • lack of scrotal hyper-pigmentation and rugae
  • decreased muscle mass and strength
  • loss of axillary and pubic hair
  • lack of facial hair
  • poor concentration and memory
  • depressed mood
  • sleep disturbance
  • hot flushes and sweats
  • increasing BMI
  • tall stature
  • fine wrinkling of facial skin

Risk factors

  • genetic anomaly
  • type 2 diabetes mellitus
  • use of alkylating agents, opioids, or glucocorticoids
  • use of exogenous sex hormones and GnRH analogues
  • hyperprolactinaemia
  • pituitary tumour or apoplexy
  • critical illness
  • testicular damage
  • varicocele
  • auto-immune testicular damage

Diagnostic investigations

Investigations to consider

  • serum sex hormone binding globulin (SHBG)
  • serum free testosterone
  • serum bioavailable testosterone
  • serum LH/FSH
  • serum prolactin
  • serum Fe, TIBC, and ferritin
  • MRI pituitary
  • semen analysis
  • genetic testing
  • serum TSH
  • dual-energy X-ray absorptiometry (DEXA or DXA)

Treatment algorithm



Charles Welliver, MD

Assistant Professor of Surgery

Division of Urology

Albany Medical College




CW has worked as a consultant for Coloplast, and as an investigator for Auxilium Pharmaceuticals, Mereo BioPharma, PROCEPT BioRobotics, and Repros; and he is a paid reviewer at Oakstone Publishing and BMJ Best Practice. CW also has a family member who is an employee at Bristol-Myers Squibb.


Dr Charles Welliver would like to gratefully acknowledge Matthew Aoun for his help with updating this topic. He would also like to acknowledge Dr T. Hugh Jones, Dr Milena Braga-Basaria, and Dr Shehzad Basaria, previous contributors to this monograph. THJ and SB are authors of references cited in this topic. MB declared that she had no competing interests.

Peer reviewers

Randal J. Urban, MD


Department of Internal Medicine

University of Texas Medical Branch




RJU declares that he has no competing interests.

Niki Karavitaki, MBBS, MSc, PhD

Consultant Endocrinologist

Oxford Centre for Diabetes, Endocrinology and Metabolism

Churchill Hospital




NK declares that she has no competing interests.

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