- Hormone forms
- Norm Testosterone
- Changes in testosterone levels with age
- Table of normal values of hormone by age
- How to pass the test for testosterone?
- Determination of testosterone levels by external signs
- When do I need to test for testosterone?
Testosterone is a hormone that is responsible for the formation of a male physique, timbre of voice, body hair, for sexual desire, sexual behavior, sperm formation. A normal amount of the main male hormone is also necessary for the cardiovascular, nervous, circulatory and urinary systems, to improve memory, performance, mental abilities.
Testosterone is classified in three forms:
- Inactive . Testosterone circulates in the blood in a complex with a specific globulin (GSM) – 35-75%. An inactive form that does not interact with receptors;
- Active. Testosterone with non-specific albumin protein – 25-65%. Because of the weak connection, it is also called conditionally free. Active (bioavailable) form;
- Free. It circulates in the blood in free form – 1-3%. Maximum bioavailable.
Total testosterone is the sum of its three forms.
The level of testosterone is influenced by internal and external factors, such as psychological state, consumed food, lifestyle, physical activity, individual characteristics of each man.
Also, the amount of hormone varies throughout the day – from the maximum concentration in the morning, to the minimum in the evening. There is a dependence of the amount of testosterone production on the season: the maximum is observed at the end of summer, the beginning of autumn, and the minimum of concentration – at the end of winter and early spring.
There is a relationship between sexuality and hormone levels. With an increased level of testosterone, the intensity of sex life increases, and with its low amount, sex life becomes difficult or impossible. Frequency of intercourse in turn affects the amount of testosterone. After a long abstinence, the level of testosterone decreases, and after sexual intercourse it increases.
Testosterone is produced at a rate of about 6-7 mg per day.
The average rate of total testosterone in the male body is in the range of 11-33 nmol / l.
Changes in testosterone levels with age
Excretion of the amount of the hormone changes with age – increases to 30 years, and then begins to decrease.
During puberty, you can observe the rapid growth of free testosterone. Thanks to this sex hormone in adolescents, the timbre of the voice changes, secondary sexual signs appear in the form of facial hair, chest in the pubic and armpit areas, muscle growth is active. For adolescents, such changes occur in the period from 11 to 18 years. Confirmation of a large amount of testosterone are night emissions, erections at night and in the early morning.
From 18 to 30 years, the average amount of hormone in the blood of men does not change. After this period, there is an annual decrease in the concentration of the hormone by an average of 1-2%.
After a 40- year-old milestone, a significant decrease in testosterone is possible, which provokes a midlife crisis.
After 50 years of age, there is a steady tendency to a decrease in the hormone, so at this age it is difficult to increase muscle mass and get rid of excess weight.
By 50-60 years, produced about half of what was produced in his youth.
With age, the cyclical changes in testosterone levels become less pronounced, so that an increase in erection gradually disappears at night and in the early morning.
After 70-75 years, against the background of a decrease in testosterone production, female sex hormones are more actively produced.
By the age of 80, the average amount of total testosterone in the blood is about 60% of its level at 20 years of age, and free testosterone is about 20%.
Table of normal values of hormone by age
|Age||Norm, nmol / l|
|0-1 years||0, 42- 0.72|
|1-7 years||0.1 – 1.12|
|7-13 years old||0.1 – 2.37|
|13-18 years old||0.98 – 38.5|
|18-50 years old||8.64 – 29|
|More than 50 years||6.68 – 25.7|
How to pass the test for testosterone?
To determine the level of male testosterone, there are several ways:
- A blood test is the most common method for determining testosterone. Results are obtained from analysis of plasma taken from a vein. In laboratories, there are two ways to calculate testosterone concentrations. These are nmol / l – nanomol per liter and pg / ml – picogram per milliliter.
- Saliva analysis is a new, simple and cheap method. It is based on the property of penetration of free hormones from capillaries into salivary flows. The concentration of testosterone in the saliva of men reflects the level of free, protein-free testosterone in the blood.
Preparation for the study
Testosterone test is taken from morning until 11 o’clock. Before the procedure itself, the following rules must be followed:
- Do not eat food 8-12 hours before the test.
- Do not load the body with excessive physical exertion during the day.
- Refrain from smoking for 4 hours.
- Do not subject the body to stressful situations.
To obtain an objective result, you need to pass the analysis several times on different days. The average value will be closest to the real indicator.
Determination of testosterone levels by external signs
Signs of Low Testosterone
In boys, during the period of sexual development, the scrotum and penis do not develop, growth slows down, and the figure is formed according to the female type with wide hips and narrow shoulders. Muscle mass does not increase, the voice remains childish, there is no hair on the chest, in the pubic area and armpits.
The following symptoms indicate decreased testosterone in adults:
- Change voice to a higher tone.
- Reduced hair growth on the body and face, or lack thereof.
- The formation of fat on the abdomen and thighs.
- Weight loss due to muscle loss, skin laxity, growth of the mammary gland.
- Constant nervousness, fatigue, shortness of breath, insomnia, severe perspiration.
- Decrease in erections at night, decrease in sexual desire.
- Decreased semen volume during ejaculation, impaired sperm production, infertility.
- Frequent reddening of the face due to hot flashes, feeling of heat.
- Memory impairment, mental impairment
It is noticed that men with low testosterone levels rarely go bald.
Signs of high testosterone.
During sexual formation, an early change in timbre of the voice, rapid puberty, growth of the penis amid lack of growth of the scrotum, early appearance of hair on the face and other parts of the body are manifested.
For adults it is characteristic:
- bouts of aggression;
- hyperexcitability and mood swings;
- increased hairiness;
- purulent acne.
Such men are distinguished by physical endurance and strength, increased sexual attraction. Externally with developed muscles, strong body hair, but often with a bald head.
When do I need to test for testosterone?
The analysis can be prescribed by doctors (endocrinologist, andrologist, urologist, fertility specialist) in such cases:
- Suspected infertility;
- Reduction or absence of libido, impairment of potency;
- In determining the causes of prostatitis;
- Rash of acne;
- Reduction of body hair growth or the lack thereof;
- Depression, irritability, memory loss;
- Weight loss due to muscle tissue.
Testosterone is the main male sex hormone that biologically affects all the tissues of the male body, supporting its vital functions. For this reason, you need to know the level of its content in the body and maintain within the normal range.