Symptoms of Low Testosterone
Low testosterone (hypogonadism) presents with a constellation of sexual, physical, psychological, and metabolic symptoms, with decreased libido and erectile dysfunction being the most characteristic features. 1
Sexual Symptoms
The most prominent and clinically significant symptoms involve sexual function:
- Reduced sex drive or libido is a primary symptom that should raise suspicion for hypogonadism 1
- Erectile dysfunction or changes in erectile function are characteristic manifestations 2, 1
- Decreased volume of ejaculate may occur 2
- Male infertility can be a presenting symptom 1
Physical and Body Composition Changes
Low testosterone affects multiple physical parameters:
- Reduced muscle mass and strength are common findings 2
- Decreased bone mineral density leading to osteoporosis risk 2, 1
- Increased body mass index or waist circumference 1
- Loss of body and facial hair in androgen-dependent areas 2, 1
- Gynecomastia (breast tissue enlargement) 1
- Small or soft testes on physical examination 1
Energy and Vitality Symptoms
Fatigue and reduced energy are hallmark features:
- Persistent fatigue and reduced energy 2, 1
- Reduced endurance and diminished work performance 1
- Diminished physical performance 1
- Weakness 2
- Diminished sense of vitality 2
Psychological and Cognitive Symptoms
Mental health manifestations are frequently present but less specific:
- Depression is a recognized symptom 2, 1
- Reduced motivation 1
- Poor concentration and impaired memory 1
- Irritability 1
- Mood disturbances 2
Metabolic Manifestations
Low testosterone is associated with several metabolic abnormalities:
- Anemia (unexplained anemia warrants testosterone measurement) 1
- Changes in body composition with increased fat mass 2
- Metabolic syndrome features including insulin resistance 3
Important Clinical Context
It is critical to understand that these symptoms are nonspecific and can result from other chronic illnesses, medications, or aging itself rather than testosterone deficiency alone. 2 The American College of Physicians notes significant uncertainty about whether these symptoms are truly consequences of low testosterone or result from other factors 2.
Diagnostic Approach
Do not rely on symptoms alone—diagnosis requires both clinical symptoms AND laboratory confirmation with two separate morning testosterone measurements below 300 ng/dL. 1 Screening questionnaires are not sufficient for diagnosis 1.
Common Pitfall
The most important caveat is that symptoms like decreased energy, vitality, physical function, or cognition are NOT reliable indicators for testosterone treatment, as evidence shows testosterone does not improve these symptoms in age-related low testosterone 2. Sexual symptoms (libido and erectile dysfunction) are the primary treatment-responsive symptoms 2.