Men's Health

Gynaecomastia (Male Breast Tissue): UK Online Doctor Guide

6 min readLast reviewed 24 April 2026

Educational information — not medical advice.

This article was prepared by the OnlineDoctor24 editorial team and reviewed for factual accuracy against UK clinical guidance (NHS and NICE). It is not written by a doctor and does not replace personal medical advice. For symptoms specific to you, book an online doctor consultation.

Key points

  • Gynaecomastia is real glandular breast tissue, distinct from fatty chest (pseudogynaecomastia).
  • Common in puberty and older age — usually benign.
  • Medications (spironolactone, finasteride, anabolic steroids) and liver disease can cause it.
  • Persistent or one-sided lumps need medical assessment.

Causes

  • Puberty (resolves in 1–2 years usually).
  • Older age (declining testosterone, rising oestrogen).
  • Medications: spironolactone, finasteride, anti-psychotics, anabolic steroids, cannabis.
  • Liver or kidney disease.
  • Rare hormone-producing tumours.

What investigations may be needed

Examination, hormone profile, liver and kidney tests, sometimes ultrasound. One-sided, hard or fixed lumps may need urgent assessment to exclude rare male breast cancer.

Treatment

  • Stop or change causative medication.
  • Treat underlying disease.
  • Tamoxifen (off-label) for persistent/painful gynaecomastia.
  • Surgery for established, distressing cases.

Red flags — when to seek urgent help

Call 999 or go to A&E if you experience any of the following:

  • Hard, one-sided or fixed lump
  • Skin dimpling or nipple discharge
  • Rapid enlargement

Frequently asked questions

Common questions UK patients ask about gynaecomastia.

How an online doctor can help

This article is for general information only and does not replace personal medical advice from a qualified doctor. Content is reviewed against UK NHS and NICE guidance by the OnlineDoctor24 editorial team and is not authored by a medical doctor. If your symptoms worsen or you are unsure, please book a consultation with a GMC-registered GP.

See a UK GP about this today

Same-day video or phone consultations with GMC-registered GPs. Prescriptions, sick notes and referrals when clinically appropriate.