This tests for a range of culprits, all of which can play a part in making you feel less than your best on a daily basis. With these answers, you can plan the next steps to improving your energy levels and finding a renewed zest for life.

This is what the test will measure:

Cortisol

Cortisol is the hormone released by our bodies in response to stress, and chronically elevated levels are known to impair our ability to sleep. Chronic stress can keep the adrenal glands on constant alert, producing cortisol too often and too much. This causes the hormone’s production to end up confused and fatigued, leading to wakeful hours at night and low energy during the day.

Thyroid-Stimulating Hormone

Thyroid-stimulating hormone, or TSH, is a hormone produced by the pituitary gland and is responsible for controlling the production of the thyroid hormones T3 and T4. Changes to your thyroid hormone production can lead to many symptoms, including lethargy and fatigue.

Vitamin D

Vitamin D is produced in the skin in response to sunlight and is crucial to your physical wellbeing. It is often referred to as the ‘sunshine’ vitamin and is important for maintaining healthy teeth, muscles, and bones, as it helps the body absorb calcium. Feeling fatigued and sluggish is probably the most common sign of vitamin D deficiency.

Hematocrit

Blood is made up of red blood cells, white blood cells and platelets, suspended in plasma. Together, those comprise about 45% of the volume of our blood, but the specific percentages of each can vary. Hematocrit is the percentage by volume of red cells in your blood.

Because the purpose of red blood cells is to transfer oxygen from the lungs to body tissues, a blood sample's hematocrit can be an indicator of its capability of delivering oxygen. If you have too many red blood cells (high hematocrit), your blood gets thicker and the risk of heart attack or stroke escalates considerably.

Hematocrit levels that are too high or too low can indicate a blood disorder, an elevated risk of dementia, dehydration or other medical conditions. An abnormally low hematocrit may suggest anemia.

For those using TRT, it’s particularly important to have your hematocrit levels checked regularly.