Causes of Low Testosterone

Hypogonadism, or low testosterone can have a variety of causes. Some of these are present from birth and others develop over time. Our medical team will discuss the background to your low testosterone levels at your initial consultation and help you understand the best course of treatment.

Primary Hypogonadism

Primary hypogonadism is a condition which stems from underactive testes that fail to produce adequate testosterone for healthy functioning. It may result from physical trauma, illness, or be caused by hereditary factors.

Inherited causes include:

Undescended testicles: A condition where the testicles do not descend from the abdomen before birth.
Klinefelter’s syndrome: A genetic disorder in which a man is born with three sex chromosomes (XXY).
Hemochromatosis: Excessive iron in the blood, potentially leading to testicular failure or damage to the pituitary gland.

Types of damage to the testicles that may result in primary hypogonadism include:

Physical trauma: Both testicles must be injured simultaneously to affect testosterone production.
Cancer treatments: Chemotherapy and radiotherapy can impair testicular function and reduce testosterone levels.
Mumps: This viral infection can damage the testes, lower fertility, and reduce testosterone output.

Secondary Hypogonadism

Secondary hypogonadism stems from dysfunction of the pituitary gland or hypothalamus, parts of the brain responsible for regulating testosterone production.

Conditions linked to secondary hypogonadism include:

Inflammatory diseases: Conditions like tuberculosis, sarcoidosis, or histiocytosis can affect the pituitary and hypothalamus.
Pituitary disorders: These can result from medication use, substance abuse, kidney failure, or small tumours.
Kallmann syndrome: A disorder related to abnormal hypothalamus function.
HIV/AIDS: This can impact the hypothalamus, pituitary, and testes, along with other bodily systems.
Other contributors to secondary hypogonadism include:

Ageing: Hormone production and regulation naturally decline with age.
Obesity: Excess body fat can interfere with hormone regulation and production.
Medications: Opioids and steroids can impair hypothalamic and pituitary function.
Existing mental or physical illnesses: Severe emotional or physical stress, including recovery from surgery or illness, can temporarily reduce testosterone production.

Mixed Hypogonadism

Mixed hypogonadism involves a combination of both primary and secondary causes. It is more common in older men and can also affect those undergoing glucocorticoid therapy (to suppress the immune system and reduce inflammation). It can also occur in individuals with conditions including sickle-cell disease, thalassemia, or chronic alcoholism.