Testosterone is the powerhouse hormone responsible for many male characteristics. It is essential for initiating and regulating puberty, the development of facial hair, sperm production, optimal energy levels, and has a role in maintaining the mood.
Beyond these characteristics, testosterone affects almost every system in the body, impacting metabolism, cognition, personality, sexual function, libido, with further links to cardiovascular risk and bone density.
If you’re feeling more tired than usual, or have observed a dip in your libido–you may be wondering if low testosterone is to blame. We’re here to provide the answers you need.
In this article, we’ll explore the most common signs and symptoms of low testosterone. If these are symptoms you recognise in yourself, we’ll guide you through potential next steps to improve your condition.
What is Testosterone?
Testosterone is the primary male sex hormone responsible for the development of male sexual characteristics. In boys, it drives the growth of sex organs, the development of body hair, and bone growth. In adult males, testosterone supports sperm production and a healthy, active libido. However, a decline in testosterone levels may lead to unwanted changes.
In women, testosterone plays a crucial role in supporting ovarian function, maintaining bone density, and promoting a healthy sex drive.
The body typically begins to produce this hormone around puberty, and slowly starts to decrease levels around the ages of 30 and 40.
Low Testosterone Explained
Low testosterone, otherwise known as male hypogonadism or testosterone deficiency (TD), occurs when the testicles do not produce sufficient amounts of testosterone to support physiological functions.
What counts as ‘normal’ testosterone levels can change from person to person. But levels are generally considered low when they fall below 12 nmol/l (or below 15nmol/l in certain patients with pre-existing medical problems such as type 2 diabetes). It is worth noting that even if you have a “normal” total testosterone, you could still be suffering with testosterone deficiency if your “free” or “available” testosterone is still low (below 0.225nmo/l).
In addition to a natural decline with age, testosterone levels may reduce because of lifestyle factors such as excessive alcohol intake, being overweight, and chronic sleep deprivation. Even mild medications including asthma treatments, antifungals, and certain painkillers, can reduce testosterone. These factors can accelerate the decrease in testosterone concentration.
Likewise, medical conditions including diabetes, liver, or kidney disease, pituitary gland or thyroid problems, HIV, AIDS, as well as side effects from chemotherapy, can also affect t levels. Although sometimes, testosterone levels may drop without a clear cause.
Most Common Testosterone Deficiency Symptoms
Testosterone is central to several physical and emotional processes. When levels of this hormone fall too low, this can cause noticeable changes in health and well-being. However, many men with low t report no significant impact on their daily life - making it important to identify how symptoms can vary.
Recognising the common symptoms of hypogonadism in males can make all the difference for early detection and prompt medical care, leading to improved life quality. Common signs and symptoms of low testosterone include:
Tiredness
Because testosterone has several key functions across the body’s energy processes, when levels of this hormone are low, many physiological processes are affected.
For example, testosterone helps to regulates metabolism and energy production - so when levels drop, energy levels also come down with it.
Similarly, testosterone support for muscle growth and maintenance comes with the downside of muscle loss and weakness when hormone levels dip. In fact, some men with low-T report struggling to build muscle despite consistent workouts at the gym.
Reduced energy production and muscle decline can make the body tire more easily, explaining the fatigue experienced under low t.
Decreased libido
If you’re experiencing a complete loss or a major reduction in your interest for sex, this can be a major indicator of low testosterone.
As the primary hormonal influence on libido, low levels of testosterone can be related to reduced interest in sexual activity, with some (but not all) men experiencing unwanted symptoms like erectile dysfunction. However, low testosterone does not automatically equate to noticeable changes in sexual activity. Some men living with this condition can enjoy regular sexual activity and interest with no challenges.
Other Possible Signs of Low-T
While reduced energy levels and a decreased libido are common physical symptoms of low testosterone levels, this condition can also manifest as emotional and cognitive reactions in patients. When levels of this hormone are low, this can produce the following low testosterone mental symptoms:
Anxiety and Low Testosterone
The body relies on a balance of hormones to carry out everyday functions. This means when one hormone, such as testosterone runs low, it can tip the balance on other chemical messengers, unsettling everything from the thyroid and prolactin, to insulin sensitivity.
Studies aren’t settled on just how low testosterone levels cause irritability, difficulty concentrating, and other symptoms of anxiety. However, there could be a link between low testosterone and a disruption in neurotransmitters like serotonin which can contribute to anxiety.
Likewise, lower testosterone levels could cause elevated cortisol levels, worsening the body’s stress responses, and raising the risk of anxiety.
Depression and Low Testosterone
Depression can be both cause and consequence of low testosterone. On one hand, testosterone helps regulate mood by influencing key neurotransmitters like serotonin, dopamine, and norepinephrine. But when t levels are low, this disrupts the balance, potentially leading to mood instability.
On the other hand, the physical effects of low testosterone - fatigue, muscle loss, and decreased libido - can dampen self-esteem and confidence, contributing to feelings of depression. This combination of hormonal imbalance and physical changes can create a cycle that worsens depressive symptoms.
Low Testosterone and Mood Swings
Men with low testosterone may experience sudden bouts of anger, anxiety, or depression - a noticeable shift from their usual emotional state.
Low testosterone disrupts the delicate balance of neurotransmitters that help regulate mood and emotional responses. These mood swings can cause a strain on relationships and overall well-being.
Low Testosterone and Concentration Issues
Low testosterone can also do a number on your ability to concentrate throughout the day. Many men report memory lapses, mental fatigue, and disorganised thinking on low T, much like menopausal women who experience brain fog. Beyond focus challenges that arise from fatigue, depression, and anxiety -conditions often associated with low testosterone - this hormonal deficiency also affects neurotransmitters like dopamine and serotonin, which are crucial for maintaining attention and mood regulation.
Hair Loss and Low Testosterone - Are They Related?
If you’re starting to notice a little less hair on your scalp, your testosterone levels - whether high or low are not to blame. Low testosterone is often mentioned in discussions about hair loss, however, this hormonal deficiency isn’t a direct cause of balding. Instead, when hair sheds, it is typically due to a genetic predisposition, known as androgenic alopecia.
Androgenic alopecia is driven by dihydrotestosterone (DHT), a potent byproduct of testosterone. Elevated levels of DHT in men more sensitive to it can cause hair follicles to shrink and weaken, eventually leading to hair loss.
So while low testosterone can indirectly influence hair loss by affecting DHT production, hair loss itself is not an immediate sign of low testosterone levels. The key factor remains a genetic sensitivity to DHT, not testosterone levels in the body.
Is Low Testosterone a Common Issue for Males?
If you’re dealing with reduced libido, low energy, or other signs of low testosterone, it can feel difficult to talk about. However, you’re not alone - many men experience similar testosterone deficiency symptoms. In fact, according to the Baltimore Longitudinal Study of Aging, nearly 40% of men over 45 face low testosterone, often due to medical conditions or lifestyle factors.
Our ADAM questionnaire is a useful tool to get some understanding about your symptoms and whether they indicate low testosterone levels. It’s designed to help you and your doctor identify the presence or severity of suspected low testosterone symptoms, guiding you toward the right course of action.
Diagnosing Low Testosterone
Our TRT doctors provide a comprehensive diagnosis to create a personalised, sustainable treatment plan that delivers real improvements. The process begins with an at-home finger-prick blood test, measuring four key biomarkers, including total and free testosterone levels. You’ll receive your results within 48 hours through your MANUAL account.
If the initial test shows low testosterone levels, UK regulations require a follow-up venous blood test performed by a nurse or phlebotomist. This more detailed test measures 43 biomarkers, confirms the initial results, and provides deeper insights into your overall health and any underlying conditions.
Following this, you’ll have a thorough consultation with a TRT doctor who will review your medical history, lifestyle, blood test results, symptoms, the risks and benefits of TRT, treatment options and costs, monitoring, and what to expect. Based on this assessment, your doctor will create a customised treatment plan with the right medication and dosage tailored to your specific needs.
Low Testosterone Treatment
Restoring testosterone to healthy levels is a unique process, requiring personalised treatment protocols.
Our doctors at MANUAL will design a bespoke TRT treatment that works specifically for you. Successful hormone therapy involves getting just the right dose by the right delivery method for your individual needs.
You’ll have the option of taking prescribed testosterone medication in the form of injectable, oral, or topical treatments. Once you start treatment, your doctor will monitor your progress and make incremental adjustments to your protocol to ensure that your body gets the right amount of testosterone to put your levels within a healthy physiological range.
How to Prevent Testosterone Loss?
While there are no current safeguards against testosterone loss caused by genetic conditions or damage to the testes, you can better your chances of maintaining healthy t levels by adopting a healthy lifestyle.
- Keep a healthy weight: Excess body fat can convert testosterone into oestrogen, lowering testosterone levels. Maintaining a healthy weight helps minimise this conversion, supporting balanced hormone levels.
- Avoid conditions like type 2 diabetes: Features of diabetes like high blood sugar and insulin resistance can reduce testosterone production.
Keeping healthy habits to lower the risk of diabetes can support optimal t levels.
- Limit alcohol intake: Limiting alcohol intake helps prevent a rise in cortisol levels, which can disrupt testosterone production. Additionally, alcohol can directly imbalance hormones, reducing testosterone levels.
- Diet and exercise: A balanced diet sources the essential nutrients needed for testosterone production. Coupled with exercise, the resulting muscle growth plus lean body fat can also help to maintain healthy t levels.
Conclusion
Low testosterone is an often overlooked but common challenge for men. If you experience persistent fatigue, reduced libido, mood changes, or other hypogonadism symptoms, talk to your doctor or take a simple at-home blood test to determine if you can benefit from testosterone treatments.
Early intervention can help restore hormonal balance and improve your quality of life.
¹The Effect of Testosterone on Cardiovascular Disease and Cardiovascular Risk Factors in Men. Hargun Kaur; Geoff H. Werstuck (2021)
²Testosterone and Bone Health in Men: A Narrative Review. Kazuyoshi Shigehara; Kouji Izumi; Yoshifumi Kadono; Atsushi Mizokami (2021)
³Male Hypogonadism. Omeed Sizar; Stephen W. Leslie; Janice Schwartz (2024)
⁴Diagnosing and managing low serum testosterone. Ana Marcella Rivas; Zachary Mulkey; Joaquin Lado-Abeal; Shannon Yarbrough (2014)
⁵Testosterone: a metabolic hormone in health and disease. Daniel M Kelly; T Hugh Jones (2013)
⁶Sex Differences in Anxiety and Depression: Role of Testosterone. Jenna McHenry; Nicole Carrier; Elaine Hull; Mohamed Kabbaj (2013)
⁷Testosterone, Estradiol, DHEA and Cortisol in relation to Anxiety and Depression scores in Adolescents. Briana NC Chronister; Eduardo Gonzalez; Dolores Lopez-Paredes; Jose Suarez-Torres (2021)
⁸The Role of Androgen in the Adipose Tissue of Males. Hyun-Ki Lee; Joo Kyung Lee; Belong Cho (2013)
