Male Hormone Blood Test Terminology

Total testosterone is the overall amount of testosterone present in your blood. Low levels of testosterone may lead to symptoms including diminished libido, reduced muscle mass and strength and low mood.

Free Testosterone is the amount of testosterone that is available for your body’s cells to use. It’s possible for total testosterone to be within the normal range while free testosterone is still low. Men with low free testosterone can experience the same symptoms as those with low total testosterone as the body doesn't have sufficient supplies to use. This often happens when there is a raised level of SHBG (sex hormone-binding globulin).  This is a protein that binds to testosterone, making it unusable by the body.

Luteinising Hormone (LH) is secreted by the pituitary gland and it plays a key role in regulating sperm production by stimulating the testes to produce testosterone.  Low LH levels can indicate potential issues with fertility.

FSH (Follicle Stimulating Hormone) is a hormone produced by the pituitary gland.  It plays a vital role in sperm production and the proper functioning of the testes in men.  In women it stimulates the function of the ovaries.

Albumin is a protein produced by the liver which plays a key role in maintaining overall health.  It acts as a carrier for important substances in the blood including hormones, enzymes and vitamins.

SHBG (sex hormone-binding globulin) is a protein made by the liver.  It binds to testosterone and other hormones in the blood stream, regulating their levels in the body.

Oestradiol is primarily a female hormone but is also produced naturally in smaller amounts in men.  It plays a crucial role in sexual function, bone health and other processes, but elevated oestradiol levels can also cause symptoms similar to low testosterone.

Prolactin is a hormone produced by the pituitary gland.  It is primarily involved in regulating reproductive and metabolic processes. While it's best known for stimulating milk production in women, prolactin also plays an important role in male health, particularly in regulating libido, testosterone production and sexual function. When you are undergoing TRT, prolactin is tested because abnormal levels—especially elevated prolactin—can indicate an underlying issue such as a hormonal imbalance.  This can interfere with the effectiveness of TRT.  High prolactin can suppress natural testosterone production and contribute to symptoms like low libido, erectile dysfunction, infertility, mood changes, and breast tissue growth (gynaecomastia). Monitoring prolactin levels helps us ensure that TRT is working properly and safely, and address your treatment protocol as needed.

A "lipid screen blood test," also called a "lipid panel" or "lipid profile," is a blood test that measures the levels of cholesterol and other types of fats (lipids) in your blood.  It measures both "good" HDL cholesterol and "bad" LDL cholesterol as well as triglycerides.  The test helps assess your risk for heart disease and stroke by identifying potential build  up of fatty deposits in your arteries.

A full blood count (FBC) is a blood test that measures the number of red blood cells, white blood cells, and platelets in your blood. It can help diagnose and monitor a variety of conditions. 

Haematocrit refers to the percentage of red blood cells in your blood and is a key marker of your body’s ability to carry oxygen. Low haematocrit levels can signal anaemia, nutritional deficiencies (such as iron, B12, or folate), chronic illness, or bone marrow disorders. Symptoms may include fatigue, weakness, shortness of breath, and pale skin—many of which overlap with low testosterone symptoms. In men with low testosterone, reduced haematocrit is not uncommon, as testosterone plays a role in stimulating red blood cell production. When testosterone levels are low, oxygen transport throughout the body can be compromised, contributing to tiredness and decreased physical performance. Conversely, during testosterone replacement therapy (TRT), haematocrit levels must be monitored closely, as testosterone can increase red blood cell production—sometimes excessively—raising the risk of thickened blood and cardiovascular complications. That’s why routine blood tests, including haematocrit measurement, are a vital part of safe and effective TRT management.

The thyroid gland plays a crucial role in maintaining overall health by regulating metabolism, heart rate, digestion, muscle strength, mood, brain function, and bone health. When thyroid function is abnormal— either underactive (hypothyroidism) or overactive (hyperthyroidism) —it can disrupt these essential processes and contribute to hormonal imbalances. In men, poor thyroid function is closely linked with low testosterone. An underactive thyroid can suppress the production of sex hormones, leading to fatigue, low libido, weight gain, and depressive symptoms that often overlap with those of low testosterone.

Deficiency in Vitamin D can lead to an increased risk of respiratory infections (e.g., colds, bronchitis, pneumonia), fatigue, bone and back pain, depression, slow wound healing, bone weakness, hair loss and muscle pain.

Elevated B12 levels may be linked to liver conditions or myeloproliferative disorders (e.g., polycythemia vera or chronic myelogenous leukaemia). Low B12 levels can result from pernicious anaemia, Crohn’s disease, coeliac disease, bacterial overgrowth, parasitic infections, or immune disorders.

A deficiency in Folate can lead to nervous system issues, temporary infertility, and heart conditions, and may cause pregnancy complications in women.

Elevated HbA1C levels indicate consistently high blood sugar levels, which may signal the presence of diabetes.

A ferritin is a protein that is tested to assess the level of iron stored in your body. 

Cortisol is a steroid hormone produced by the adrenal glands.  It is often referred to as the "stress hormone" but it also plays a key role in regulating various metabolic functions.  We test it to assess how well your pituitary and adrenal glands are functioning.