Everything you need to know about low testosterone
Get clued up about the symptoms of low testosterone and find out how you can get checked.
What is testosterone?
Testosterone is a male steroid hormone known as an androgen. In men testosterone is mainly produced in the testes and is responsible for the male reproductive system and the production of sperm. Testosterone is also responsible for male characteristics that appear at puberty and in adolescence when testosterone levels surge. These include the maturation of the penis and the testicles, growth in body hair and deepening of the voice as well as increasing muscle mass. Testosterone also plays an important role in libido (sex drive), mood and behaviour (e.g. aggression and competitive spirit).
What is low testosterone?
Testosterone levels can be measured in the blood where the result will be shown against a reference range. However, all laboratories will slightly differ in the reference ranges they apply because they are based on the population they are testing. The normal range is set so that 95% of men will fall into it. For greater consistency, we use the guidance from the British Society for Sexual Medicine (BSSM) which advises that low testosterone can be diagnosed when testosterone is consistently below 8 nmol/L and that levels below 12 nmol/L could also be considered low, especially in men who also report symptoms of low testosterone, or who have low levels of free testosterone.
What causes low testosterone?
Low testosterone can be caused by the inability of the testes to produce enough testosterone due to a genetic or inherited condition (e.g. Klinefelter’s syndrome or the failure of the testes to descend into the scrotum), infection or injury to the testicles. This is known as primary hypogonadism.
Secondary hypogonadism occurs when testosterone production falls as a result of problems with the hypothalamus or pituitary glands which regulate testosterone production. Rarely, tumours can cause pressure on the glands which can affect their ability to produce the hormones which stimulate the testes to produce testosterone.
Other causes of low testosterone include:
- Type 2 diabetes
- Some medications e.g. opioids
- Testicular cancer and cancer treatment
- Anabolic androgenic steroid (AAS) use
Does getting older cause low testosterone?
Testosterone levels naturally decline with age and usually begin reducing from 30 onwards. This is a gradual decline that many men may never notice and indeed, 80% of older men retain testosterone levels within the normal range. However, for some men, symptoms of low testosterone become gradually more apparent, especially as they reach their 50s and 60s. This is sometimes known as the male menopause or andropause and is thought of as the equivalent to the decline in reproductive hormones that women experience during the menopause.
Why does taking anabolic androgenic steroids (AASs) cause low testosterone?
Anabolic steroids are synthetic forms of testosterone and are often taken by men to improve athletic performance and build muscle. If the body is flooded with artificial testosterone, the glands in the brain which regulate testosterone (the hypothalamus and the pituitary) sense high circulating testosterone levels and essentially switch off production of testosterone in the testicles. This causes the testicles to shrink, which reduces their ability to produce testosterone again once steroid use stops. Previous use of AASs is a common cause of low testosterone and can affect men of any age.
What are the symptoms of low testosterone?
Low testosterone can affect the physical and mental health of men in the following ways:
- Low libido
- Erectile dysfunction
- Low muscle mass
- Loss of strength
- Increased body fat
- Gynaecomastia (growth of breast tissue)
- Lack of self-esteem
- Lack of motivation
- Low energy and fatigue
- Small testicles
- Low semen volume
- Decreased bone density
- Hair loss
- Difficulties sleeping
How is low testosterone diagnosed?
Low testosterone is diagnosed with a blood test to measure the amount of testosterone in the body. Your testosterone levels will be highest in the morning so you should take your test shortly after you wake up. If your testosterone is found to be low, our doctors will normally recommend a repeat test to confirm.
We also have a testosterone test with an extended upper range which is useful for men taking TRT or anabolic steroids who expect to have supranormal levels of testosterone.
How is low testosterone treated?
Low testosterone can be treated by your doctor who can prescribe testosterone replacement therapy (TRT). Testosterone can be replaced by synthetic forms of testosterone in gel form (which can be rubbed on the skin and absorbed), by intramuscular injection, patches and subcutaneous implants. Testosterone is less commonly prescribed as an oral tablet because it can be damaging to the liver.
Are there natural ways to increase testosterone?
You may be able to boost your testosterone levels by making some adjustments to your diet and lifestyle. The following methods have shown some success in increasing testosterone:
- Getting between 7 and 9 hours of sleep per night
- Eating a diet rich in healthy fats, protein and carbs
- Avoiding alcohol
- Exercise especially strength training
- Minimising stress and therefore cortisol production
- Increasing vitamin D through sun exposure or supplements
- Losing weight if you need to
- Increasing magnesium and zinc through diet or supplements
You can check your testosterone levels, along with other key hormones, with our Male Hormone Blood Test
Testosterone Home Blood Test
TRT (Testosterone Replacement Therapy) Blood Test