Low testosterone (male hypogonadism) means low testosterone levels together with symptoms. The diagnosis needs both: clear symptoms and a low morning blood test repeated at least twice. Low testosterone is a treatable cause of low desire and erectile dysfunction.
Medically reviewed by Prof. Dr. Samir Ahmed Al-Samarrai, consultant urologist. Last reviewed:
What are the symptoms of low testosterone?
The symptoms most linked to low testosterone are sexual:
- Low sexual desire.
- Erectile dysfunction.
- Fewer morning erections.
Less specific symptoms include persistent tiredness, poor concentration, low mood, loss of muscle and more belly fat. These have many other causes, so they are not enough for a diagnosis on their own.
Who is more likely to have low testosterone?
- Men with obesity, type 2 diabetes or metabolic syndrome.
- Men with chronic illness.
- Men taking medicines or substances that affect hormone production, such as anabolic steroids used for bodybuilding.
- Men with conditions of the testicles or the pituitary gland.
How is low testosterone diagnosed?
According to the European Association of Urology (EAU) 2025 guidelines:
- Total testosterone is measured in the morning between 7 and 11 am while fasting, and repeated at least once if below 12 nmol/L and before any treatment.
- LH and FSH show the type: a problem in the testicles or in the pituitary gland.
- Prolactin in specific cases, such as low desire with secondary hypogonadism.
- Free testosterone is calculated from SHBG when the doctor needs it.
Routine screening of all men is not recommended; testing is for men with symptoms. Related blood tests are explained in erectile dysfunction tests.
How is low testosterone treated?
- Treat the cause and improve lifestyle first: weight loss, diabetes control, treating other conditions and stopping medicines that affect hormones where possible.
- Testosterone therapy for men with symptoms and confirmed low levels who are not planning to have children. The doctor chooses the form, such as gel or injection.
- With erectile dysfunction: testosterone is the first treatment when erectile dysfunction is mild, and is combined with ED tablets in more severe cases.
When is testosterone not used?
- When testosterone levels are normal.
- To lose weight or improve heart and metabolic health.
- To improve energy, strength or memory in older men without a confirmed deficiency.
- To treat infertility, or in men planning to have children.
Never take testosterone or anabolic steroids without a prescription and medical follow-up.
What monitoring is needed during treatment?
- Assessment of heart risk factors before starting.
- Testosterone and haematocrit at 3, 6 and 12 months, then every year.
- If haematocrit rises above 54%, the doctor adjusts or stops treatment.
- Prostate follow-up according to age and medical history.
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Frequently asked questions
What is a normal testosterone level?
European guidelines use 12 nmol/L (3.5 ng/mL) of total testosterone as the threshold for late-onset hypogonadism. A blood test alone is not enough: the diagnosis needs symptoms plus repeated low results.
Does testosterone treatment affect fertility?
Yes. Taking testosterone reduces sperm production, so it is not used to treat infertility. Tell your doctor if you plan to have children before starting any treatment.
Should every tired man have his testosterone checked?
No. Tiredness and low mood have many causes. Testing is for men with symptoms, especially sexual symptoms such as low desire and erectile dysfunction, and the doctor decides after an assessment.
Can testosterone improve without hormone treatment?
In some men it can, after weight loss, better diabetes control, treating chronic illness and reviewing medicines that affect hormones. Guidelines start with these steps before hormone treatment.
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Prof. Al-Samarrai and Dr. Amer Mousa assess low testosterone at Prof. Al-Samarrai Medical Center, Dubai Healthcare City, and choose the tests and treatment each case needs.
This information is for health education and does not replace a medical examination. See our medical content policy.