Testosterone deficiency: symptoms, diagnosis and treatment

24 Mar

Testosterone deficiency — medically known as hypogonadism — affects an estimated 2-6% of all men, but the number in the dark is likely to be significantly higher. Many live with the symptoms for years without associating fatigue, decreased libido and low mood with low testosterone. The line between normal aging and treatment-requiring deficiency is not always clear, and the diagnosis requires more than a single blood test. Here we go through the most common testosterone deficiency symptoms, how diagnostics work in Sweden in 2026, which reference values ​​apply and which treatment options are available.

Testosterone deficiency symptoms — how do you recognize low testosterone?

The symptoms of low testosterone often creep in gradually, making them difficult to distinguish from normal aging, stress or depression. It is rarely a single symptom, but rather a combination that gives rise to the suspicion of testosterone deficiency.

The most common symptoms men report with documented testosterone deficiency:

• Decreased sexual desire (libido) — the most specific symptom. Testosterone drives spontaneous sexual desire, and a marked reduction in sexual thoughts, fantasies, and initiative often signals hormonal deficiency rather than relationship-related causes.

• Erectile dysfunction — difficulty achieving or maintaining an erection, especially the absence of a morning erection. Testosterone does not directly control erection (nitric oxide does), but deficient levels impair neurological signaling.

• Fatigue and lack of energy not explained by sleep patterns — an exhaustion that persists regardless of how much sleep you get. Differentiate from temporary fatigue: testosterone-related fatigue is chronic and persistent.

• Decreased muscle mass and increased body fat percentage — sarconpenia (muscle breakdown) combined with increased abdominal fat storage, despite unchanged diet and exercise.

• Depression, irritability and difficulty concentrating — low testosterone affects the serotonin and dopamine systems in the brain. The symptoms overlap strongly with depression, which leads to many men being wrongly diagnosed with depression and put on SSRIs instead of being investigated hormonally.

• Decreased bone mass (osteopenia/osteoporosis) — rarely symptomatic until a fracture occurs, but measurable on DEXA scan.

None of these symptoms are unique to testosterone deficiency — each individual symptom can have other causes. It is the combination and the chronic pattern that make a hormonal investigation should be considered.

Age is a natural factor. Testosterone levels decline by about 1–2% per year after age 30, and by 60, the average man has 20–30% lower testosterone compared to his levels at 25. However, this natural decline is not considered hypogonadism if values ​​are within the reference range and symptoms are mild. The line between normal aging and treatment-requiring deficiency is one of the most debated questions in endocrinology — and the answer varies depending on which specialist you ask.

Certain medications can also cause or worsen low testosterone. Opioids (such as tramadol and morphine), long-term cortisone treatment, 5-alpha reductase inhibitors (finasteride for hair loss), and SSRIs can all lower testosterone levels. If you are taking any of these and experience symptoms that match, the relationship with the medication should be investigated before TRT is considered.

Diagnostics — how is hypogonadism diagnosed in Sweden?

The diagnosis of testosterone deficiency requires two components: laboratory-confirmed low testosterone plus clinical symptoms. Low values ​​alone without symptoms do not warrant treatment, and conversely — symptoms without confirmatory lab values ​​should be investigated for alternative causes.

Which blood samples are needed and which reference values ​​apply?

Blood samples should be taken in the morning (7am-10am), as testosterone follows a circadian rhythm with highest levels early in the morning. Sampling in the afternoon can give falsely low values ​​with up to 30% deviation. At least two separate sampling occasions are required before the diagnosis can be made — a single low value may be due to temporary factors such as lack of sleep, stress or acute illness.

The following parameters are analyzed:

|Analysis|Reference value (adult men)|Comment|

|Total testosterone|8–30 nmol/L|Below 8 = deficiency, 8–12 = gray area|

|Free testosterone|170–500 pmol/L|More informative in borderline cases|

|SHBG|15–55 nmol/L|High SHBG binds more T → lower free T|

|LH|1.5–9.3 IU/L|High LH + low T = primary hypogonadism|

|FSH|1.4–18.1 IU/L|High FSH + low T = testicular dysfunction|

|Prolactin|<20 µg/L|Elevated may indicate a pituitary tumor|

Primary hypogonadism (testicular related) is characterized by low testosterone plus high LH — the pituitary gland tries to compensate by sending more stimulation, but the testicles don’t respond. Secondary hypogonadism (hypothalamic/pituitary related) shows low testosterone plus low or normal LH — the signal from the brain is insufficient. Do you want to understand more about how testosterone is produced and regulated? Read our guide to the different types of testosterone.

Testosterone deficiency treatment — from lifestyle to TRT

The treatment depends on the cause, degree of severity and the patient’s wishes regarding fertility. Lifestyle measures are always tried first in borderline cases (total testosterone 8–12 nmol/L), while testosterone replacement therapy (TRT) is considered in clear deficiency (below 8 nmol/L) with symptoms.

Lifestyle intervention can produce measurable effect in men with secondary hypogonadism caused by obesity, lack of sleep or chronic stress. Weight loss in obesity can raise testosterone by 2–3 nmol/L per 10% body weight loss—an effect well documented in studies of obese men with low levels. Sleep optimization (7–9 hours per night of quality sleep), active stress reduction via meditation or priority work, and strength training with a focus on heavy multi-joint exercises add up. However, these measures take 3–6 months to show results and are rarely sufficient in severe deficiency (below 6 nmol/L).

Alcohol consumption deserves a special mention. Regular consumption of more than 2-3 standard glasses per day lowers testosterone measurably by direct toxic effect on the Leydig cells in the testicles and by increasing aromatase activity (conversion of testosterone to estrogen). Reducing or eliminating alcohol can be one of the fastest lifestyle measures to have an effect on testosterone levels — improvement is often seen in as little as 2-4 weeks.

TRT is most commonly administered in Sweden as injections (testosterone undecanoate every 10–14 weeks, or testosterone enanthate/cypionate every 1–2 weeks), gel (daily application) or patches. Injections provide the most stable levels, while gel offers convenience but requires daily application and caution around skin contact with children and partners. Read our in-depth on different testosterone forms for a detailed comparison of the preparations.

Risks, side effects and follow-up with testosterone treatment

TRT is not risk-free and requires regular medical follow-up. Before starting treatment, PSA levels should be checked (screening for prostate cancer), and follow-up blood tests should be taken every 3-6 months for the first year and annually thereafter.

The most common side effects of TRT include polycythemia (increased red blood cell count, occurs in 3-18% and requires monitoring), acne and increased skin oiliness, fluid retention (mild), and suppressed sperm production — the latter of which makes TRT directly unsuitable for men planning to become fathers. Alternative treatments such as clomiphene or HCG can stimulate the body’s own testosterone production without shutting down spermatogenesis, but these are rarely prescribed in Swedish primary care and often require a specialist.

An important distinction: testosterone deficiency that is properly diagnosed and treated often results in significant symptom improvement—increased energy, improved libido, better mood, and restored muscle mass within 3-6 months. Many patients describe it as “the veil being lifted” — an experience that clearly illustrates how profound testosterone’s effects are on quality of life.

However, testosterone treatment in men with normal levels does not provide the same benefits and carries unnecessary risk. Correct diagnosis before treatment is non-negotiable. In Sweden, the waiting times for an endocrinologist can be 3–6 months, but some private clinics offer a faster examination — expect SEK 2,000–5,000 for a complete hormone panel including consultation.

.entry-content