Hypogonadism
Hypogonadism occurs when the testes or ovaries fail to produce adequate levels of sex hormones. In men, the most commonly affected group, this means chronically low testosterone, which affects energy, libido, mood, bone density, and muscle mass. It can develop at any age, though it becomes more prevalent with age and is increasingly recognised in men with metabolic conditions such as type 2 diabetes or obesity.
Key points
- Primary hypogonadism starts in the testes themselves, for example after trauma, mumps infection or a genetic condition such as Klinefelter syndrome.
- When the fault lies higher up, in the pituitary gland or hypothalamus, the condition is classed as secondary hypogonadism.
- Testosterone replacement is the main treatment and tends to improve energy and sexual function gradually, often within a few months.
Why testosterone levels fall
Primary hypogonadism originates in the testes themselves, damage from trauma, infection (including mumps orchitis), or genetic conditions such as Klinefelter syndrome. Secondary hypogonadism arises higher up, when the pituitary gland or hypothalamus fails to send the right signals, often due to a tumour, iron overload, or prolonged use of certain medicines. A simple blood test measuring morning testosterone, LH, and FSH distinguishes the two types and guides treatment.
Restoring hormone levels
Hormone therapy is the mainstay of treatment. Testosterone replacement brings levels back into the normal range, relieving fatigue, improving sexual function, and supporting bone and muscle health over time. Response is gradual; most men notice meaningful improvement within a few months of consistent therapy. Regular monitoring of haematocrit, prostate health, and hormone levels is standard practice during long-term treatment.