Hypogonadism
|
Hypogonadism Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Hypogonadism On the Web |
|
American Roentgen Ray Society Images of Hypogonadism |
For patient information click here
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords: Low T
Overview
Hypogonadism is a medical term for a defect of the reproductive system which results in lack of function of the gonads (ovaries or testes). The gonads have two functions: to produce hormones (testosterone, estradiol, antimullerian hormone, progesterone, inhibin B), activin and to produce gametes (eggs or sperm). Deficiency of sex hormones can result in defective primary or secondary sexual development, or withdrawal effects (e.g., premature menopause) in adults. Defective egg or sperm development results in infertility. The term hypogonadism is usually applied to permanent rather than transient or reversible defects, and usually implies deficiency of reproductive hormones, with or without fertility defects. The term is less commonly used for infertility without hormone deficiency.
Classification
There are many possible types of hypogonadism and several ways to categorize them.
by Congenital vs. acquired
- An example of congenital hypogonadism (present at birth) is Turner syndrome.
- An example of acquired hypogonadism (develops in childhood or adult life) is castration.
by Hormones vs. fertility
Hypogonadism can involve just hormone production or just fertility, but most commonly involves both.
- Examples of hypogonadism that affect hormone production more than fertility are hypopituitarism and Kallmann syndrome; in both cases fertility is reduced until hormones are replaced but can be achieved solely with hormone replacement.
- Examples of hypogonadism that affect fertility more than hormone production are Klinefelter syndrome and Kartagener syndrome.
by Affected system
Hypogonadism is also categorized by endocrinologists by the level of the reproductive system which is defective.
- Hypogonadism resulting from defects of the gonads is traditionally referred to as primary hypogonadism. Examples include Klinefelter syndrome and Turner syndrome.
- Hypogonadism resulting from hypothalamic or pituitary defects are termed secondary hypogonadism or central hypogonadism (referring to the central nervous system).
- Examples of Hypothalamic defects include Kallmann syndrome
- Examples of Pituitary defects include hypopituitarism
- An example of a hypogonadism resulting from hormone response is androgen insensitivity syndrome
Symptoms
Low Testosterone (Low T) symptoms include loss of energy, fatigue, loss of libido, muscle mass decline, decreased positive mood factors and an increased negative mood factors.
Diagnosis
Low Testosterone can be identified through a simple blood test performed by a physician. Normal testosterone levels range from 298 - 1098 ng/dl. Physicians measure gonadotropins (LH and FSH) to distinguish primary from secondary hypogonadism. In primary hypogonadism the LH and/or FSH are usually elevated, while in secondary hypogonadism both are normal or low.
Hypogonadism is often discovered during evaluation of delayed puberty, but ordinary delay which eventually results in normal pubertal development and reproductive function is termed.
Treatment
Hypogonadism is most often treated by replacement of the appropriate hormones. For men this is testosterone. Commonly used testosterone formulations include transdermal testosterone, injectable testosterone, and buccal testosterone. Oral testosterone is no longer used in the U.S. because it is broken down in the liver and rendered inactive. Another feasible alternative is hCG. For women estradiol and progesterone are replaced. Some types of fertility defects can be treated; some cannot.
References
External links