Basic Thyroid Panel

A thyroid panel are tests that are often ordered together to help evaluate thyroid gland function. These tests measure the amount of thyroid hormones circulating in the blood. Thyroid hormones are chemical messengers that travel through the blood and regulate the body's metabolism and how it functions and uses energy.

A Thyroid panel usually includes:

• TSH (thyroid-stimulating hormone) – this tests for hypothyroidism , hyperthyroidism and to monitor treatment for a thyroid disorder. This tells how hard the brain is telling the thyroid to produce hormones.
• Free T4 (thyroxine) – to test for hypothyroidism and hyperthyroidism; may also be used to monitor treatment
• Free T3 or total T3 (triiodothyronine) – to test for hyperthyroidism; may also be used to monitor treatment

TSH is produced by the pituitary gland and is part of the body's feedback system to maintain stable amounts of the thyroid hormones T3 and T4 in the blood. When thyroid hormone levels drop too low, the pituitary releases TSH. TSH in turn stimulates the production and release of T4 and T3 by the thyroid gland. When the system is functioning normally, thyroid production turns on and off to maintain constant blood thyroid hormone levels. T3 and T4 help to regulate the body’s metabolic function and energy levels. While this is not the only hormone that controls the metabolism it is a key hormone to look at.

T3 and T4 easily bind to proteins in the blood and then are not as effective on the metabolism. Tests for free and bound T3 and or T4 can be run and will give a much better idea of metabolic function. Very often T3/T4 bound and unbound tests are done to show a total number and what is available for use. If you are having issues like fatigue and weight gain it might be better to get T3/T4 bound and unbound testing.

Prostate specific antigen (PSA) is produced primarily in the prostate . Most of the PSA that the prostate produces is released into the seminal fluid, but small amounts of it are also released into the blood. PSA exists in two forms in the blood: complex (cPSA, which is the bound variant) and free (fPSA, not bound). The most frequently used PSA test is the total PSA, this measures the sum of cPSA and fPSA.

The PSA test may be used as a tumor marker to screen for and to monitor prostate cancer. The goal of screening is to detect prostate cancer while it is still confined to the prostate. PSA levels will also increase due to inflammation and a process called benign prostatic hyperplasia where the prostate swells. PSA levels tend to increase in all men as they age. Black males also have an increased level of risk. PSA is not diagnostic of cancer. The gold standard for identifying prostate cancer is a prostate biopsy , collecting small samples of prostate tissue and identifying abnormal cells under the microscope. An elevated PSA may be followed by a biopsy, which has risk of complications such as pain, fever, blood in the urine, or urinary tract infection .

DHT is critical for the development of male genitalia during the process of embryogenesis. DHT is also important during the maturation of the penis, scrotum, seminal vesicles and prostate as men develop into maturity. Facial, pubic, and body hair growth depend on DHT as well. DHT is produced from the less potent testosterone by the enzyme 5 α -reductase in specialized tissue such as the prostate, testicles, adipose tissue, hair and skin.

Levels of DHT in the blood are 1/10th and 1/20th those of testosterone in terms of total and free concentrations, however, local DHT levels may be up to 10 times those of testosterone in tissues with high 5α-reductase enzymes such as the prostate.

Testosterone and DHT play major roles in the development of men during puberty. Testosterone is responsible for:

• Spermatogenesis and fertility- The development of viable sperm
• The male physique- The development of the musculoskeletal frame.
• Deeper voice
• Oily skin- Testosterone increases sebum production which is an oil and can lead to acne.
• Libido- Sexual desire
• Erectile function- Helps to create harder erections.

DHT is responsible for:

• Prostate enlargement- This is critical during puberty, however, if DHT levels stay high for too long prostate cancer risk start to increase markedly.
• Facial, axillary, pubic, and over all body hair growth.
• Scalp and forehead recession style hair loss- Male pattern balding. This can happen in women as well if the levels of DHT get too high.

Testosterone is involved in health and well-being, the prevention of osteoporosis and other significant quality of life issues. Insufficient levels of testosterone in men may lead to abnormalities including, anxiety, depression, weight gain, fatigue, erectile dysfunction, brain fog, frailty and bone loss.

Testosterone has also been shown to be critical to the health and well being in women. From muscle building, fat loss, energy, emotional stability, brain function, and overall bodily function.

Testosterone is also the primary sex hormone in men . In men, testosterone plays a key role in the development of reproductive tissues such as prostate and testes , as well as promoting secondary sex characteristics such as increased bone and muscle mass, as well as an increase in body hair growth.

Estrogen

Estrogens are a group of steroids that are responsible for the development and function of reproductive organs, aid in pregnancy, and the formation of secondary sex characteristics in women. Along with another hormone , progesterone , they help regulate the menstrual cycle, are involved in the growth of breasts and the uterus, and help maintain a healthy pregnancy . Though considered the main sex hormones for women, they are also found in men and play a role in bone metabolism and growth in both sexes. Estrogen labs measure one of three types of estrogen: estrone (E1), estradiol (E2), or estriol (E3) in the blood or urine.

• Estrone (E1) is directly converted from androstenedione (from the adrenal gland ) or indirectly from other androgens . E1 can also be produced by the ovaries and placenta , testicles, and adipose (fat) tissues. E2 and E1 can be converted into each other as needed. E1 is the primary estrogen in men and in post- menopausal women.
• Estradiol (E2) is primarily produced in the ovaries in response to stimulation of FSH and LH in pre-menopausal women and in the testicles in men. E2 is converted from E1 in post-menopausal women. It is the most potent estrogen and the one that is present in the highest concentration in non-pregnant, pre-menopausal women. E2 levels vary depending on a woman's age and reproductive status. They are a good marker of ovarian function.
• Estriol (E3) is produced by the placenta, with concentrations rising throughout a woman's pregnancy. Increasing levels are an indication of the health of the pregnancy and developing baby. Estriol is part of the second trimester maternal serum screen , a test performed to evaluate fetal risk due to certain chromosomal abnormalities. Very low levels of E3 are present in non-pregnant women or men.