What are the symptoms of high testosterone?

In men, the signs of high testosterone are acne and oily skin, faster hair loss, thicker blood, breast tissue growth, shrinking testicles and lower fertility. Almost all of them come from testosterone taken from outside: steroids, over-dosed TRT or a "supplement" that contained more than it said. Naturally high testosterone is uncommon and usually produces no symptoms at all.

That is the useful starting point, because many men who search this are either worried about a high blood result or wondering whether their mood or drive means their testosterone is high. Mood and drive are poor guides. A blood test, read properly, is the only way to know.

Signs of high testosterone in men

• Acne and oily skin, often on the back and shoulders, in a man who has not had spots for years. Testosterone converts to DHT, which drives the skin's oil glands.
• Faster scalp hair loss in men who carry the genes for it. More androgen speeds up male pattern baldness; it does not thicken hair. See testosterone and hair loss.
• Thicker blood. Testosterone raises red blood cell production. A haematocrit above 54 per cent raises the risk of clots, and it is the finding doctors act on fastest.
• Breast tissue growth (gynaecomastia). Extra testosterone is converted into oestradiol, so more testosterone can mean more oestrogen. See gynaecomastia.
• Smaller testicles and a lower sperm count, when the testosterone comes from outside. The brain stops signalling the testes, so they stop making both testosterone and sperm. This is the clearest sign of all.
• Poor sleep, irritability and raised blood pressure in some men. The link to aggression is weaker than its reputation: controlled studies of high doses find modest effects that vary a lot between men.

Notice that none of these is something a man would want. There is no symptom of high testosterone that feels like extra health.

How to tell if you have high testosterone

Only a blood test can tell you, and one result is not enough. Most UK laboratories put the upper limit for total testosterone at around 30 nmol/L. Before reading anything into a high number:

• Repeat it on a separate morning, before 11am. Testosterone is highest early in the day, so an early sample reads higher than an afternoon one.
• Stop biotin for two or three days first. High-dose biotin, sold for hair and nails, interferes with many hormone tests and can produce a falsely high or low result.
• Ask for LH and FSH. This pair is the key. High testosterone with very low LH means it is coming from outside the body. High testosterone with normal or high LH means the body is making it, which needs investigating.
• Ask for SHBG and free testosterone. A man with naturally high SHBG can show a high total while his free, usable testosterone is normal. See what SHBG is.
• Ask for a full blood count, which includes haematocrit.

More on getting a result you can trust: the testosterone blood test guide and how to read your blood test results.

What causes high testosterone in men

Something being taken, by a wide margin. Prescribed TRT at too high a dose, or a sample taken a day or two after an injection; anabolic steroids; and supplements bought online that contain undeclared hormones. Shop-bought testosterone boosters do not raise levels into the high range on their own. See TRT versus steroids.

A misleading test: timing, biotin, a single reading or a high SHBG.

Rare medical causes: testicular tumours (Leydig cell tumours), adrenal tumours, tumours that make hCG, and a mild form of congenital adrenal hyperplasia. They are uncommon, but they are why a persistently high level in a man taking nothing deserves a specialist opinion rather than reassurance. A new testicular lump always needs seeing promptly.

Signs of high testosterone in teenage boys

During puberty, testosterone rises steeply, and the signs people search for, such as spots, a growth spurt, a deeper voice, body hair and a stronger sex drive, are normal puberty rather than a problem. A blood level that looks high by adult standards can be normal for a teenager.

Two situations do need a GP. The NHS advises seeing one if signs of puberty start before the age of 8. And a teenager whose testicles are shrinking, or who has acne, rapid muscle gain and mood changes all at once, may be using steroids or unregulated "gym" products. That is a conversation worth having early, because steroids at this age can stunt final height and disrupt the body's own hormone production.

What about women?

High testosterone is more common and more important in women, most often because of polycystic ovary syndrome. The signs are irregular or absent periods, acne, extra facial or body hair and thinning hair on the scalp. See PCOS symptoms.

When to see a GP

• A high testosterone result that is still high on a repeat morning test, especially if you take nothing.
• A testicular lump, or testicles that are shrinking.
• Breast swelling or tenderness.
• A haematocrit above 54 per cent, or headaches, flushing and dizziness while on testosterone.
• You are on TRT and have acne, thick blood or smaller testicles: that is a dose and monitoring question for your prescriber, and usually easy to fix. See TRT side effects.

If your level is naturally at the top of the range and you feel well, nothing needs doing. That is a normal variation, not a condition.

The full guide: High testosterone symptoms in men, and when it's a problem covers the rare causes, laboratory pitfalls and why more testosterone is not better, in depth. Related: does testosterone make men take risks? · normal testosterone levels by age · does TRT cause infertility?

Sources: Endocrine Society 2018, Testosterone therapy in men with hypogonadism · Travison et al. 2017, harmonised testosterone reference ranges · NHS: early or delayed puberty