How hormone replacement therapy works

Hormone replacement therapy is a method of treatment that involves replacement or substitution of naturally occurring hormones. It is used in instances where there are deficiencies of certain hormones. Examples of commonly used methods of hormone replacement therapy are post menopausal hormone replacement therapy, hormone replacement for transgender gender variant and transsexuals, and androgen replacement therapy. Out of these, post menopausal hormone replacement therapy is the most widely used and well known type of hormone replacement therapy.

In post menopausal period the female body deprives of Estrogen and progesterone. As a result of this they experience post menopausal symptoms such as hot flashes, night sweats, vaginal dryness, sleeping disturbances etc. Post menopausal hormone replacement therapy replaces the above two deficient hormones. Estrogen is taken from plants or from urine of pregnant horses. Progesterone is given as progestogen which is a synthetic form of progesterone.

Osteoporosis is a major cause of morbidity in post-menopausal women. Hormone replacement therapy is one way of treatment of osteoporosis. Estrogen is involved in preventing bone loss and maintaining bone density by suppressing osteoclastogenic cytokine production in T-cells and osteoblasts and by inducing the apoptotic death of osteoclasts. The protection from osteoporosis is lost in post-menopausal period because the body deprives of estrogen. This leads to increased risk of fractures.  Therefore, the reduced amounts of estrogen and progesterone is substituted in hormone replacement therapy, so they go and act on bone osteoblasts and osteoclasts and prevent further bone loss. But the use of hormone replacement therapy is initiated cautiously because it caries a risk of breast cancer and cardiovascular disease. Therefore, it is mainly given for perimenopausal women with osteoporosis with other menopausal symptoms.

Premature ovarian failure is another instance where hormone replacement therapy is started. In this case, the ovaries fail to secrete estrogen and progesterone at a younger age. These patients are at higher risk of developing osteoporosis and heart diseases. Such patients are started on hormone replacement therapy to supplement the deficient hormones.

As with any other treatment methods hormone replacement therapy also caries side effects. They are mainly breast carcinoma, coronary heart disease, stroke and formation of blood clots. Therefore, the benefits should always outweigh the risks to start hormone replacement therapy. One should be extra cautious if the patient is already having another systemic illness.

Finally, hormone replacement therapy can be described as a method to replace the body’s deficient hormones. But, it is not as simple as that, because it also caries risks. Naturally, the amount of hormones secreted by the body is regulated by several feedback mechanisms, but in hormone replacement therapy, this is not regulated the same way. This can lead to adverse effects.

Referances: Kumar and Clark’s Clinical Medicine, 7^th Edition